Contents
Correlation rules
Correlation rules are used to recognize specific sequences of processed events and to take certain actions after recognition, such as creating correlation events/alerts or interacting with an active list.
Correlation rules can be used in the following KUMA services and features:
- Correlator.
- Notification rule.
- Links of segmentation rules.
- Retroscan.
The available correlation rule settings depend on the selected type. Types of correlation rules:
- standard—used to find correlations between several events. Resources of this kind can create correlation events.
This rule kind is used to determine complex correlation patterns. For simpler patterns you should use other correlation rule kinds that require less resources to operate.
- simple—used to create correlation events if a certain event is found.
- operational—used for operations with Active lists and context tables. This rule kind cannot create correlation events.
For these resources, you can enable the display of control characters in all input fields except the Description field.
If a correlation rule is used in the correlator and an alert was created based on it, any change to the correlation rule will not result in a change to the existing alert even if the correlator service is restarted. For example, if the name of a correlation rule is changed, the name of the alert will remain the same. If you close the existing alert, a new alert will be created and it will take into account the changes made to the correlation rule.
Standard correlation rules
Standard correlation rules are used to identify complex patterns in processed events.
The search for patterns is conducted by using buckets
The correlation rule window contains the following tabs:
- General—used to specify the main settings of the correlation rule. On this tab, you can select the type of correlation rule.
- Selectors—used to define the conditions that the processed events must fulfill to trigger the correlation rule. Available settings vary based on the selected rule type.
- Actions—used to set the triggers that will activate when the conditions configured in the Selectors settings block are fulfilled. The Correlation rule resource must have at least one trigger. Available settings vary based on the selected rule type.
- Correlators—used for linking correlators. Available only for created correlation rules that are open for editing.
General tab
- Name (required)—a unique name for this type of resource. Must contain 1 to 128 Unicode characters.
- Tenant (required)—the tenant that owns the correlation rule.
- Type (required)—a drop-down list for selecting the type of correlation rule. Select standard if you want to create a standard correlation rule.
- Identical fields (required)—the event fields that should be grouped in a Bucket. The hash of the values of the selected fields is used as the Bucket key. If the selector (see below) triggers, the selected fields will be copied to the correlation event.
If different selectors of the correlation rule use fields that have different values in events, do not specify these fields in the Identical fields section.
- Unique fields—event fields that should be sent to the Bucket. If this parameter is set, the Bucket will receive only unique events. The hash of the selected fields' values is used as the Bucket key.
You can use local variables in the Identical fields and Unique fields sections. To access a variable, its name must be preceded with the "$" character.
For an example of using local variables in these sections, refer to the rule provided with KUMA: R403_Access to malicious resources from a host with disabled protection or an out-of-date anti-virus database. - Rate limit—maximum number of times a correlation rule can be triggered per second. The default value is 100.
If correlation rules employing complex logic for pattern detection are not triggered, this may be due to the specific method used to count rule triggers in KUMA. In this case, try to increase the value of Rate limit to
1000000
, for example. - Window, sec (required)—bucket lifetime, in seconds. Default value: 86,400 seconds (24 hours). This timer starts when the Bucket is created (when it receives the first event). The lifetime is not updated, and when it runs out, the On timeout trigger from the Actions group of settings is activated and the bucket is deleted. The On every threshold and On subsequent thresholds triggers can be activated more than once during the lifetime of the bucket.
- Base events keep policy—this drop-down list is used to specify which base events must be stored in the correlation event:
- first (default value)—this option is used to store the first base event of the event collection that triggered creation of the correlation event.
- last—this option is used to store the last base event of the event collection that triggered creation of the correlation event.
- all—this option is used to store all base events of the event collection that triggered creation of the correlation event.
- Priority—base coefficient used to determine the importance of a correlation rule. The default value is Low.
- Order by—in this drop-down list, you can select the event field that will be used by the correlation rule selectors to track situational changes. This could be useful if you want to configure a correlation rule to be triggered when several types of events occur sequentially, for example.
- Description—the description of a resource. Up to 4,000 Unicode characters.
Selectors tab
A rule of the standard kind can have multiple selectors. You can add selectors by clicking the Add selector button and can remove them by clicking the Delete selector button. Selectors can be moved by using the button.
For each selector, the following two tabs are available: Settings and Local variables.
The Settings tab contains the following settings:
- Alias (required)—unique name of the event group that meets the conditions of the selector. Must contain 1 to 128 Unicode characters.
- Selector threshold (event count) (required)—the number of events that must be received by the selector to trigger. The default value is 1.
- Filter (required)—used to set the criteria for determining events that should trigger the selector. You can select an existing filter from the drop-down list or create a new filter.
Creating a filter in resources
Filtering based on data from the Extra event field
The order of conditions specified in the selector filter of the correlation rule is significant and affects system performance. We recommend putting the most unique condition in the first place in the selector filter.
Consider two examples of selector filters that select successful authentication events in Microsoft Windows.
Selector filter 1:
Condition 1. DeviceProduct = Microsoft Windows
Condition 2. DeviceEventClassID = 4624
Selector filter 2:
Condition 1. DeviceEventClassID = 4624
Condition 2. DeviceProduct = Microsoft Windows
The order of conditions in Selector filter 2 is preferable because it causes less load on the system.
- Recovery—this check box must be selected when the Correlation rule must NOT trigger if a certain number of events are received from the selector. By default, this check box is cleared.
Select the Local variables tab and click Add variable to declare variables that you want to use within the limits of this correlation rule.
In the selector of the correlation rule, you can use regular expressions conforming to the RE2 standard.
Using regular expressions in correlation rules is computationally intensive compared to other operations. Therefore, when designing correlation rules, we recommend limiting the use of regular expressions to the necessary minimum and using other available operations.
To use a regular expression, you must use the match
comparison operator. The regular expression must be placed in a constant. The use of capture groups in regular expressions is optional. For the correlation rule to trigger, the field text matched against the regexp must exactly match the regular expression.
For a primer on syntax and examples of correlation rules that use regular expressions in their selectors, see the following rules that are provided with KUMA:
- R105_04_Suspicious PowerShell commands. Suspected obfuscation.
- R333_Suspicious creation of files in the autorun folder.
Actions tab
A rule of the standard kind can have multiple triggers.
- On first threshold—this trigger activates when the Bucket registers the first triggering of the selector during the lifetime of the Bucket.
- On subsequent thresholds—this trigger activates when the Bucket registers the second and all subsequent triggering of the selector during the lifetime of the Bucket.
- On every threshold—this trigger activates every time the Bucket registers the triggering of the selector.
- On timeout—this trigger activates when the lifetime of the Bucket ends, and is linked to the selector with the Recovery check box selected. In other words, this trigger activates if the situation detected by the correlation rule is not resolved within the defined amount of time.
Every trigger is represented as a group of settings with the following parameters available:
- Output—if this check box is selected, the correlation event is sent for post-processing: for external enrichment outside the correlation rule, for response, and to destinations.
- Loop to correlator—if this check box is selected, the created correlation event is processed by the rule chain of the current correlator. This allows hierarchical correlation.
If the Output and Loop to correlator check boxes are set, the correlation rule is sent to post-processing first, and then to the selectors of the current correlation rule.
- Do not create alert—if this check box is selected, an alert is not created when this correlation rule is triggered. If you do not want to create an alert when a correlation rule is triggered, but you still want to send a correlation event to the storage, select the Output and No alert check boxes. If you select only the No alert check box, a correlation event is not saved in the storage.
- Under Enrichment, you can modify the fields of correlation events by using enrichment rules. These enrichment rules are stored in the correlation rule where they were created. You can create multiple enrichment rules. Enrichment rules can be added or deleted by using the Add enrichment or Remove enrichment buttons, respectively.
- Source kind—you can select the type of enrichment in this drop-down list. Depending on the selected type, you may see advanced settings that will also need to be completed.
Available types of enrichment:
- Debug—you can use this toggle switch to enable logging of service operations.
- Description—the description of a resource. Up to 4,000 Unicode characters.
- Source kind—you can select the type of enrichment in this drop-down list. Depending on the selected type, you may see advanced settings that will also need to be completed.
- Categorization settings group—used to change the categories of assets indicated in events. There can be several categorization rules. You can add or delete them by using the Add categorization or Remove categorization buttons. Only reactive categories can be added to assets or removed from assets.
- Operation—this drop-down list is used to select the operation to perform on the category:
- Add—assign the category to the asset.
- Delete—unbind the asset from the category.
- Event field—event field that indicates the asset requiring the operation.
- Category ID—the drop-down list displays a tree of categories, in which you can select a category to perform the operation on. Clicking the row expands the list.
- Operation—this drop-down list is used to select the operation to perform on the category:
- Active lists update group of settings—used to assign the trigger for one or more operations with active lists. You can use the Add active list action and Delete active list action buttons to add or delete operations with active lists, respectively.
Available settings:
- Name (required)—this drop-down list is used to select the Active list resources.
- Operation (required)—this drop-down list is used to select the operation that must be performed:
- Sum—add a constant, the value of a correlation event field, or the value of a local variable to the value of the active list.
- Get—get the Active list entry and write the values of the selected fields into the correlation event.
- Set—write the values of the selected fields of the correlation event into the Active list by creating a new or updating an existing Active list entry. When the Active list entry is updated, the data is merged and only the specified fields are overwritten.
- Delete—delete the Active list entry.
- Key fields (required)—this is the list of event fields used to create the Active list entry. It is also used as the Active list entry key.
The active list entry key depends on the available fields and does not depend on the order in which they are displayed in the KUMA web interface.
- Mapping (required for Get and Set operations)—used to map Active list fields with events fields. More than one mapping rule can be set.
- The left field is used to specify the Active list field.
The field must not contain special characters or numbers only.
- The middle drop-down list is used to select event fields.
- The right field can be used to assign a constant to the Active list field is the Set operation was selected.
- Under Context table update, you can assign the trigger for one or more operations with context tables. You can click "Add context table action" or "Delete context table action" to add or delete operations with context tables.
- Available settings:
- Name (required)—this drop-down list is used to select context table resources.
- Operation (required)—this drop-down list is used to select the operation that must be performed.
- Sum—add a constant, the value of a correlation event field, or the value of a local variable to the value of the context table. This operation is used only for fields of number and float types.
- Set—write the values of the selected fields of the correlation event into the context table by creating a new or updating an existing context table entry. When the context table entry is updated, the data is merged and only the specified fields are overwritten.
- Get—get the fields of the context table and write the values of the specified fields into the correlation event. Table fields of the boolean type and lists of boolean values are excluded from mapping because the event does not contain boolean fields.
- Merge—append the value of a correlation event field, local variable, or constant to the current value of a field of the context table.
- Delete—delete the context table entry.
- Key fields (required)—this is the list of event fields used to create the context table entry. It is also used as the key of the context table entry. As a key field, you can specify an event field or a local variable declared on the "Selectors" tab.
- The composite key of the context table entry depends only on the values of fields and does not depend on the order in which they are displayed in the KUMA web interface.
- Mapping (required for all operations except "Delete")—used to map context table fields to event fields or variables. More than one mapping rule can be set. You can specify the same context table field multiple times.
- The left field is used to specify the context table field.
- The field must not contain a field name that is already used in the mapping, tab characters, special characters, or only numerals. The maximum number of characters is 128. The name cannot begin with an underscore.
- The middle drop-down list is used to select event fields or a local variable.
- The right field can be used to assign a constant to the context table field is the "Set" operation was selected. "Merge" or "Sum". The maximum number of characters is 1,024.
- The left field is used to specify the Active list field.
Correlators tab
- Add—Used when editing the created correlation rule. You can click Add to open the Correlators window and select a correlator from the list. After you click OK, the rule is linked to the selected correlator. You can select multiple correlators at the same time. The rule is added to the end of the execution queue. If you want to move the rule up in the execution queue, go to Resources - Correlator - <selected correlator> - Edit correlator - Correlation, select the check box next to the relevant rule and use the Move up or Move down buttons to reorder the rules as necessary.
- Delete—Used to unlink the correlation rule from the correlator.
Simple correlation rules
Simple correlation rules are used to define simple sequences of events.
The correlation rule window contains the following settings tabs:
- General—used to specify the main settings of the correlation rule. On this tab, you can select the type of correlation rule.
- Selectors—used to define the conditions that the processed events must fulfill to trigger the correlation rule. Available settings vary based on the selected rule kind.
- Actions—used to set the triggers that will activate when the conditions configured in the Selectors settings block are fulfilled. A correlation rule must have at least one trigger. Available settings vary based on the selected rule type.
- Correlators—used for linking correlators. Available only for created correlation rules that are open for editing.
General tab
- Name (required)—a unique name for this type of resource. Must contain 1 to 128 Unicode characters.
- Tenant (required)—the tenant that owns the correlation rule.
- Type (required)—a drop-down list for selecting the type of correlation rule. Select simple if you want to create a simple correlation rule.
- Propagated fields (required)—event fields used for event selection. If the selector (see below) is triggered, these fields will be written to the correlation event.
- Rate limit—maximum number of times a correlation rule can be triggered per second. The default value is 100.
If correlation rules employing complex logic for pattern detection are not triggered, this may be due to the specific method used to count rule triggers in KUMA. In this case, try to increase the value of Rate limit to
1000000
, for example. - Priority—base coefficient used to determine the importance of a correlation rule. The default value is
Low
. - Description—the description of a resource. Up to 4,000 Unicode characters.
Selectors tab
A rule of the simple kind can have only one selector for which the Settings and Local variables tabs are available.
The Settings tab contains settings with the Filter group of settings:
- Filter (required)—used to set the criteria for determining events that should trigger the selector. You can select an existing filter from the drop-down list or create a new filter.
Creating a filter in resources
Filtering based on data from the Extra event field
The order of conditions specified in the selector filter of the correlation rule is significant and affects system performance. We recommend putting the most unique condition in the first place in the selector filter.
Consider two examples of selector filters that select successful authentication events in Microsoft Windows.
Selector filter 1:
Condition 1. DeviceProduct = Microsoft Windows
Condition 2. DeviceEventClassID = 4624
Selector filter 2:
Condition 1. DeviceEventClassID = 4624
Condition 2. DeviceProduct = Microsoft Windows
The order of conditions in Selector filter 2 is preferable because it causes less load on the system.
Select the Local variables tab and click Add variable to declare variables that you want to use within the limits of this correlation rule.
Actions tab
A rule of the simple kind can have only one trigger: On every event. It is activated every time the selector triggers.
Available parameters of the trigger:
- Output—if this check box is selected, the correlation event is sent for post-processing: for enrichment, for a response, and to destinations.
- Loop to correlator—if this check box is selected, the created correlation event is processed by the rule chain of the current correlator. This allows hierarchical correlation.
If the Output and Loop to correlator check boxes are set, the correlation rule is sent to post-processing first, and then to the selectors of the current correlation rule.
- Do not create alert—if this check box is selected, an alert is not created when this correlation rule is triggered. If you do not want to create an alert when a correlation rule is triggered, but you still want to send a correlation event to the storage, select the Output and No alert check boxes. If you select only the No alert check box, a correlation event is not saved in the storage.
- Enrichment settings group—you can modify the fields of correlation events by using enrichment rules. These enrichment rules are stored in the correlation rule where they were created. You can create multiple enrichment rules. Enrichment rules can be added or deleted by using the Add enrichment or Remove enrichment buttons, respectively.
- Source kind—you can select the type of enrichment in this drop-down list. Depending on the selected type, you may see advanced settings that will also need to be completed.
Available types of enrichment:
- Debug—you can use this toggle switch to enable logging of service operations.
- Description—the description of a resource. Up to 4,000 Unicode characters.
- Filter settings block—lets you select which events will be forwarded for enrichment. Configuration is performed as described above.
- Source kind—you can select the type of enrichment in this drop-down list. Depending on the selected type, you may see advanced settings that will also need to be completed.
- Categorization settings group—used to change the categories of assets indicated in events. There can be several categorization rules. You can add or delete them by using the Add categorization or Remove categorization buttons. Only reactive categories can be added to assets or removed from assets.
- Operation—this drop-down list is used to select the operation to perform on the category:
- Add—assign the category to the asset.
- Delete—unbind the asset from the category.
- Event field—event field that indicates the asset requiring the operation.
- Category ID—the drop-down list displays a tree of categories, in which you can select a category to perform the operation on. Clicking the row expands the list.
- Operation—this drop-down list is used to select the operation to perform on the category:
- Active lists update group of settings—used to assign the trigger for one or more operations with active lists. You can use the Add active list action and Delete active list action buttons to add or delete operations with active lists, respectively.
Available settings:
- Name (required)—this drop-down list is used to select the active list.
- Operation (required)—this drop-down list is used to select the operation that must be performed:
- Sum—add a constant, the value of a correlation event field, or the value of a local variable to the value of the active list.
- Get—get the Active list entry and write the values of the selected fields into the correlation event.
- Set—write the values of the selected fields of the correlation event into the Active list by creating a new or updating an existing Active list entry. When the Active list entry is updated, the data is merged and only the specified fields are overwritten.
- Get—get the Active list entry and write the values of the selected fields into the correlation event.
- Delete—delete the Active list entry.
- Key fields (required)—this is the list of event fields used to create the Active list entry. It is also used as the Active list entry key.
The active list entry key depends on the available fields and does not depend on the order in which they are displayed in the KUMA web interface.
- Mapping (required for Get and Set operations)—used to map Active list fields with events fields. More than one mapping rule can be set.
- The left field is used to specify the Active list field.
The field must not contain special characters or numbers only.
- The middle drop-down list is used to select event fields.
- The right field can be used to assign a constant to the Active list field is the Set operation was selected.
- The left field is used to specify the Active list field.
- Under Context table update, you can assign the trigger for one or more operations with context tables. You can click "Add context table action" or "Delete context table action" to add or delete operations with context tables.
- Available settings:
- Name (required)—this drop-down list is used to select context table resources.
- Operation (required)—this drop-down list is used to select the operation that must be performed.
- Sum—add a constant, the value of a correlation event field, or the value of a local variable to the value of the context table. This operation is used only for fields of number and float types.
- Set—write the values of the selected fields of the correlation event into the context table by creating a new or updating an existing context table entry. When the context table entry is updated, the data is merged and only the specified fields are overwritten.
- Get—get the fields of the context table and write the values of the specified fields into the correlation event. Table fields of the boolean type and lists of boolean values are excluded from mapping because the event does not contain boolean fields.
- Merge—append the value of a correlation event field, local variable, or constant to the current value of a field of the context table.
- Delete—delete the context table entry.
- Key fields (required)—this is the list of event fields used to create the context table entry. It is also used as the key of the context table entry. As a key field, you can specify an event field or a local variable declared on the "Selectors" tab.
- The composite key of the context table entry depends only on the values of fields and does not depend on the order in which they are displayed in the KUMA web interface.
- Mapping (required for all operations except "Delete")—used to map context table fields to event fields or variables. More than one mapping rule can be set. You can specify the same context table field multiple times.
- The left field is used to specify the context table field.
- The field must not contain a field name that is already used in the mapping, tab characters, special characters, or only numerals. The maximum number of characters is 128. The name cannot begin with an underscore.
- The middle drop-down list is used to select event fields or a local variable.
- The right field can be used to assign a constant to the context table field is the "Set" operation was selected. "Merge" or "Sum". The maximum number of characters is 1,024.
Correlators tab
- Add—Used when editing the created correlation rule. You can click Add to open the Correlators window and select a correlator from the list. After you click OK, the rule is linked to the selected correlator. You can select multiple correlators at the same time. The rule is added to the end of the execution queue. If you want to move the rule up in the execution queue, go to Resources - Correlator - <selected correlator> - Edit correlator - Correlation, select the check box next to the relevant rule and use the Move up or Move down buttons to reorder the rules as necessary.
- Delete—Used to unlink the correlation rule from the correlator.
Operational correlation rules
Operational correlation rules are used for working with active lists.
The correlation rule window contains the following tabs:
- General—used to specify the main settings of the correlation rule. On this tab, you can select the type of correlation rule.
- Selectors—used to define the conditions that the processed events must fulfill to trigger the correlation rule. Available settings vary based on the selected rule type.
- Actions—used to set the triggers that will activate when the conditions configured in the Selectors settings block are fulfilled. A correlation rule must have at least one trigger. Available settings vary based on the selected rule type.
- Correlators—used for linking correlators. Available only for created correlation rules that are open for editing.
General tab
- Name (required)—a unique name for this type of resource. Must contain 1 to 128 Unicode characters.
- Tenant (required)—the tenant that owns the correlation rule.
- Type (required)—a drop-down list for selecting the type of correlation rule. Select operational if you want to create an operational correlation rule.
- Rate limit—maximum number of times a correlation rule can be triggered per second. The default value is 100.
If correlation rules employing complex logic for pattern detection are not triggered, this may be due to the specific method used to count rule triggers in KUMA. In this case, try to increase the value of Rate limit to
1000000
, for example. - Description—the description of a resource. Up to 4,000 Unicode characters.
Selectors tab
A rule of the operational kind can have only one selector for which the Settings and Local variables tabs are available.
The Settings tab contains settings with the Filter group of settings:
- Filter (required)—used to set the criteria for determining events that should trigger the selector. You can select an existing filter from the drop-down list or create a new filter.
On the Local variables tab, click Add variable to declare variables that you want to use within the limits of this correlation rule.
Actions tab
A rule of the operational kind can have only one trigger: On every event. It is activated every time the selector triggers.
Available parameters of the trigger:
- Active lists update group of settings—used to assign the trigger for one or more operations with active lists. You can use the Add active list action and Delete active list action buttons to add or delete operations with active lists, respectively.
Available settings:
- Name (required)—this drop-down list is used to select the active list.
- Operation (required)—this drop-down list is used to select the operation that must be performed:
- Sum—add a constant, the value of a correlation event field, or the value of a local variable to the value of the active list.
- Set—write the values of the selected fields of the correlation event into the Active list by creating a new or updating an existing Active list entry. When the Active list entry is updated, the data is merged and only the specified fields are overwritten.
- Delete—delete the Active list entry.
- Key fields (required)—this is the list of event fields used to create the Active list entry. It is also used as the Active list entry key.
The active list entry key depends on the available fields and does not depend on the order in which they are displayed in the KUMA web interface.
- Mapping (required for Set operation)—used to map active list fields with event fields. More than one mapping rule can be set.
- The left field is used to specify the Active list field.
The field must not contain special characters or numbers only.
- The middle drop-down list is used to select event fields.
- The right field can be used to assign a constant to the Active list field is the Set operation was selected.
- The left field is used to specify the Active list field.
- Under Context table update, you can assign the trigger for one or more operations with context tables. You can click Add context table action or Delete context table action to add or delete operations with context tables, respectively.
Available settings:
- Name (required)—this drop-down list is used to select context table resources.
- Operation (required)—this drop-down list is used to select the operation that must be performed.
- Sum—add a constant, the value of a correlation event field, or the value of a local variable to the value of the context table. This operation is used only for fields of number and float types.
- Set—write the values of the selected fields of the correlation event into the context table by creating a new or updating an existing context table entry. When the context table entry is updated, the data is merged and only the specified fields are overwritten.
- Merge—append the value of a correlation event field, local variable, or constant to the current value of a field of the context table.
- Delete—delete the context table entry.
- Key fields (required)—this is the list of event fields used to create the context table entry. It is also used as the key of the context table entry. As a key field, you can specify an event field or a local variable declared on the Selectors tab.
The composite key of the context table entry depends only on the values of fields and does not depend on the order in which they are displayed in the KUMA web interface.
- Mapping (required for all operations except Delete)—used to map context table fields to event fields or variables. More than one mapping rule can be set. You can specify the same context table field multiple times.
- The left field is used to specify the context table field.
The field must not contain a field name that is already used in the mapping, tab characters, special characters, or only numerals. The maximum number of characters is 128. The name cannot begin with an underscore.
- The middle drop-down list is used to select event fields or a local variable.
- You can use the right field to assign a constant to the context table field. The maximum number of characters is 1024.
- The left field is used to specify the context table field.
Correlators tab
- Add—Used when editing the created correlation rule. You can click Add to open the Correlators window and select a correlator from the list. After you click OK, the rule is linked to the selected correlator. You can select multiple correlators at the same time. The rule is added to the end of the execution queue. If you want to move the rule up in the execution queue, go to Resources - Correlator - <selected correlator> - Edit correlator - Correlation, select the check box next to the relevant rule and use the Move up or Move down buttons to reorder the rules as necessary.
- Delete—Used to unlink the correlation rule from the correlator.
Variables in correlators
If tracking values in event fields, active lists, or dictionaries is not enough to cover some specific security scenarios, you can use global and local variables. You can use them to take various actions on the values received by the correlators by implementing complex logic for threat detection. Variables can be declared in the correlator (global variables) or in the correlation rule (local variables) by assigning a function to them, then querying them from correlation rules as if they were ordinary event fields and receiving the triggered function result in response.
Usage scope of variables:
- When searching for identical or unique field values in correlation rules.
- In the correlation rule selectors, in the filters of the conditions under which the correlation rule must be triggered.
- When enriching correlation events. Select Event as the source type.
- When populating active lists with values.
Variables can be queried the same way as event fields by preceding their names with the $ character.
Local variables in identical and unique fields
You can use local variables in the Identical fields and Unique fields sections of 'standard' type correlation rules. To use a local variable, its name must be preceded with the "$" character.
For an example of using local variables in the Identical fields and Unique fields sections, refer to the rule provided with KUMA: R403_Access to malicious resources from a host with disabled protection or an out-of-date anti-virus database.
Page topLocal variables in selector
To use a local variable in a selector:
- Add a local variable to the rule.
- In the Correlation rules window, go to the General tab and add the created local variable to the Identical fields section. Prefix the local variable name with a "$" character.
- In Correlation rules window, go to the Selectors tab, select an existing filter or create a new filter and click Add condition.
- Select the event field as the operand.
- Select the local variable as the event field value and prefix the variable name with a "$" character.
- Specify the remaining filter settings.
- Click Save.
For an example of using local variables, refer to the rule provided with KUMA: R403_Access to malicious resources from a host with disabled protection or an out-of-date anti-virus database.
Page topLocal Variables in event enrichment
You can use 'standard' and 'simple' correlation rules to enrich events with local variables.
Enrichment with text and numbers
You can enrich events with text (strings). To do so, you can use functions that modify strings: to_lower, to_upper, str_join, append, prepend, substring, tr, replace, str_join.
You can enrich events with numbers. To do so, you can use the following functions: addition ("+"), subtraction ("-"), multiplication ("*"), division ("/"), round, ceil, floor, abs, pow.
You can also use regular expressions to manage data in local variables.
Using regular expressions in correlation rules is computationally intensive compared to other operations. Therefore, when designing correlation rules, we recommend limiting the use of regular expressions to the necessary minimum and using other available operations.
Timestamp enrichment
You can enrich events with timestamps (date and time). To do so, you can use functions that let you get or modify timestamps: now, extract_from_timestamp, parse_timestamp, format_timestamp, truncate_timestamp, time_diff.
Operations with active lists and tables
You can enrich events with local variables and data from active lists and tables.
To enrich events with data from an active list, use the active_list, active_list_dyn functions.
To enrich events with data from a table, use the table_dict, dict functions.
You can create conditional statements by using the 'conditional' function in local variables. In this way, the variable can return one of the values depending on what data was received for processing.
Enriching events with a local variable
To use a local variable to enrich events:
- Add a local variable to the rule.
- In the Correlation rules window, go to the General tab and add the created local variable to the Identical fields section. Prefix the local variable name with a "$" character.
- In the Correlation rules window, go to the Actions tab, and under Enrichment, in the Source kind drop-down list, select Event.
- From the Target field drop-down list, select the KUMA event field to which you want to pass the value of the local variable.
- From the Source field drop-down list, select a local variable. Prefix the local variable name with a "$" character.
- Specify the remaining rule settings.
- Click Save.
Local variables in active list enrichment
You can use local variables to enrich active lists.
To enrich the active list with a local variable:
- Add a local variable to the rule.
- In the Correlation rules window, go to the General tab and add the created local variable to the Identical fields section. Prefix the local variable name with a "$" character.
- In the Correlation rules window, go to the Actions tab and under Active lists update, add the local variable to the Key fields field. Prefix the local variable name with a "$" character.
- Under Mapping, specify the correspondence between the event fields and the active list fields.
- Click the Save button.
Properties of variables
Local and global variables
The properties of global variables differ from the properties of local variables.
Global variables:
- Global variables are declared at the correlator level and are applied only within the scope of this correlator.
- The global variables of the correlator can be queried from all correlation rules that are specified in it.
- In standard correlation rules, the same global variable can take different values in each selector.
- It is not possible to transfer global variables between different correlators.
Local variables:
- Local variables are declared at the correlation rule level and are applied only within the limits of this rule.
- In standard correlation rules, the scope of a local variable consists of only the selector in which the variable was declared.
- Local variables can be declared in any type of correlation rule.
- Local variables cannot be transferred between rules or selectors.
- A local variable cannot be used as a global variable.
Variables used in various types of correlation rules
- In operational correlation rules, on the Actions tab, you can specify all variables available or declared in this rule.
- In standard correlation rules, on the Actions tab, you can provide only those variables specified in these rules on the General tab, in the Identical fields field.
- In simple correlation rules, on the Actions tab, you can provide only those variables specified in these rules on the General tab, in the Inherited Fields field.
Requirements for variables
When adding a variable function, you must first specify the name of the function, and then list its parameters in parentheses. Basic mathematical operations (addition, subtraction, multiplication, division) are an exception to this requirement. When these operations are used, parentheses are used to designate the severity of the operations.
Requirements for function names:
- Must be unique within the correlator.
- Must contain 1 to 128 Unicode characters.
- Must not begin with the character $.
- Must be written in camelCase or CamelCase.
Special considerations when specifying functions of variables:
- The sequence of parameters is important.
- Parameters are separated by a comma:
,
. - String parameters are passed in single quotes:
'
. - Event field names and variables are specified without quotation marks.
- When querying a variable as a parameter, add the
$
character before its name. - You do not need to add a space between parameters.
- In all functions in which a variable can be used as parameters, nested functions can be created.
Functions of variables
Operations with active lists and dictionaries
"active_list" and "active_list_dyn" functions
These functions allow you to receive information from an active list and dynamically generate a field name for an active list and key.
You must specify the parameters in the following sequence:
- Name of the active list.
- Expression that returns the field name of the active list.
- One or more expressions whose results are used to generate the key.
Usage example
Result
active_list('Test', to_lower('DeviceHostName'), to_lower(DeviceCustomString2), to_lower(DeviceCustomString1))
Gets the field value of the active list.
Use these functions to query the active list of the shared tenant from a variable. To do so, add the @Shared suffix after the name of the active list (case sensitive). For example, active_list('exampleActiveList@Shared', 'score', SourceAddress, SourceUserName).
"table_dict" function
Gets information about the value in the specified column of a dictionary of the table type.
You must specify the parameters in the following sequence:
- Dictionary name.
- Dictionary column name.
- One or more expressions whose results are used to generate the dictionary row key.
Usage example
Result
table_dict('exampleTableDict', 'office', SourceUserName)
Gets data from the
exampleTableDict
dictionary from the row with theSourceUserName
key in theoffice
column.table_dict('exampleTableDict', 'office', SourceAddress, to_lower(SourceUserName))
Gets data from the
exampleTableDict
dictionary from a composite key string from theSourceAddress
field value and the lowercase value of theSourceUserName
field from theoffice
column.
Use this function to access the dictionary of the shared tenant from a variable. To do so, add the @Shared
suffix after the name of the active list (case sensitive). For example, table_dict('exampleTableDict@Shared', 'office', SourceUserName)
.
"dict" function
Gets information about the value in the specified column of a dictionary of the dictionary type.
You must specify the parameters in the following sequence:
- Dictionary name.
- One or more expressions whose results are used to generate the dictionary row key.
Usage example
Result
dict('exampleDictionary', SourceAddress)
Gets data from
exampleDictionary
from the row with theSourceAddress
key.dict('exampleDictionary', SourceAddress, to_lower(SourceUserName))
Gets data from the
exampleDictionary
from a composite key string from theSourceAddress
field value and the lowercase value of theSourceUserName
field.
Use this function to access the dictionary of the shared tenant from a variable. To do so, add the @Shared
suffix after the name of the active list (case sensitive). For example, dict('exampleDictionary@Shared', SourceAddress)
.
Operations with context tables
"context_table" function
Returns the value of the specified field in the base type (for example, integer, array of integers).
You must specify the parameters in the following sequence:
- Name of the context table. The name must be specified.
- Expression that returns the field name of context table.
- Expression that returns the name of key field 1 of the context table.
- Expression that returns the value of key field 1 of the context table.
The function must contain at least 4 parameters.
Usage example |
Result |
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"len" function
Returns the length of a string or array.
The function returns the length of the array if the passed array is of one of the following types:
- array of integers
- array of floats
- array of strings
- array of booleans
If an array of a different type is passed, the data of the array is cast to the string type, and the function returns the length of the resulting string.
Usage examples |
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"distinct_items" function
Returns a list of unique elements in an array.
The function returns the list of unique elements of the array if the passed array is of one of the following types:
- array of integers
- array of floats
- array of strings
- array of booleans
If an array of a different type is passed, the data of the array is cast to the string type, and the function returns a string consisting of the unique characters from the original string.
Usage examples |
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"sort_items" function
Returns a sorted list of array elements.
You must specify the parameters in the following sequence:
- Expression that returns the object of the sorting.
- Sorting order Possible values:
asc
,desc
. If the parameter is not specified, the default value isasc
.
The function returns the list of sorted elements of the array if the passed array is of one of the following types:
- array of integers
- array of floats
- array of strings
For a boolean array, the function returns the list of array elements in the original order.
If an array of a different type is passed, the data of the array is cast to the string type, and the function returns a string of sorted characters.
Usage examples |
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"item" function
Returns the array element with the specified index or the character of a string with the specified index if an array of integers, floats, strings, or boolean values is passed.
You must specify the parameters in the following sequence:
- Expression that returns the object of the indexing.
- Expression that returns the index of the element or character.
The function must contain at least 2 parameters.
The function returns the array element with the specified index or the string character with the specified index if the index falls within the range of the array and the passed array is of one of the following types:
- array of integers
- array of floats
- array of strings
- array of booleans
If an array of a different type is passed and the index falls within the range of the array, the data is cast to the string type, and the function returns the string character with the specified index. If an array of a different type is passed and the index is outside the range of the array, the function returns an empty string.
Usage examples |
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Operation with rows
"len" function
Returns the number of characters in a string. Supported for standard fields and extended event schema fields of the "string" type.
A string can be passed as a string, field name or variable.
Usage examples |
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"to_lower" function
Converts characters in a string to lowercase. Supported for standard fields and extended event schema fields of the "string" type.
A string can be passed as a string, field name or variable.
Usage examples |
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"to_upper" function
Converts characters in a string to uppercase. Supported for standard fields and extended event schema fields of the "string" type. A string can be passed as a string, field name or variable.
Usage examples |
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"append" function
Adds characters to the end of a string. Supported for standard fields and extended event schema fields of the "string" type.
You must specify the parameters in the following sequence:
- Original string.
- Added string.
Strings can be passed as a string, field name or variable.
Usage examples |
Usage result |
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The string |
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The string |
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A string from |
"prepend" function
Adds characters to the beginning of a string. Supported for standard fields and extended event schema fields of the "string" type.
You must specify the parameters in the following sequence:
- Original string.
- Added string.
Strings can be passed as a string, field name or variable.
Usage examples |
Usage result |
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The string |
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The string |
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A string from |
"substring" function
Returns a substring from a string. Supported for standard fields and extended event schema fields of the "string" type.
You must specify the parameters in the following sequence:
- Original string.
- Substring start position (natural number or 0).
- (Optional) substring end position.
Strings can be passed as a string, field name or variable. If the position number is greater than the original data string length, an empty string is returned.
Usage examples |
Usage result |
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Returns a part of the string from the |
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Returns a part of the string from the |
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Returns the entire string from the |
"tr" function
Deletes the specified characters from the beginning and end of a string. Supported for standard fields and extended event schema fields of the "string" type.
You must specify the parameters in the following sequence:
- Original string.
- (Optional) string that should be removed from the beginning and end of the original string.
Strings can be passed as a string, field name or variable. If you do not specify a string to be deleted, spaces will be removed from the beginning and end of the original string.
Usage examples |
Usage result |
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Spaces have been removed from the beginning and end of the string from the |
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If the |
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If the |
"replace" function
Replaces all occurrences of character sequence A in a string with character sequence B. Supported for standard fields and extended event schema fields of the "string" type.
You must specify the parameters in the following sequence:
- Original string.
- Search string: sequence of characters to be replaced.
- Replacement string: sequence of characters to replace the search string.
Strings can be passed as an expression.
Usage examples |
Usage result |
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Returns a string from the |
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Returns a string from |
"regexp_replace" function
Replaces a sequence of characters that match a regular expression with a sequence of characters and regular expression capturing groups. Supported for standard fields and extended event schema fields of the "string" type.
You must specify the parameters in the following sequence:
- Original string.
- Search string: regular expression.
- Replacement string: sequence of characters to replace the search string, and IDs of the regular expression capturing groups. A string can be passed as an expression.
Strings can be passed as a string, field name or variable. Unnamed capturing groups can be used.
In regular expressions used in variable functions, each backslash character must be additionally escaped. For example, ^example\\\\
must be used instead of the regular expression ^example\\
.
Usage examples |
Usage result |
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Returns a string from the |
"regexp_capture" function
Gets the result matching the regular expression condition from the original string. Supported for standard fields and extended event schema fields of the "string" type.
You must specify the parameters in the following sequence:
- Original string.
- Search string: regular expression.
Strings can be passed as a string, field name or variable. Unnamed capturing groups can be used.
In regular expressions used in variable functions, each backslash character must be additionally escaped. For example, ^example\\\\
must be used instead of the regular expression ^example\\
.
Usage examples |
Example values |
Usage result |
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Operations with timestamps
now function
Gets a timestamp in epoch format. Runs with no arguments.
Usage examples |
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"extract_from_timestamp" function
Gets atomic time representations (year, month, day, hour, minute, second, day of the week) from fields and variables with time in the epoch format.
The parameters must be specified in the following sequence:
- Event field of the timestamp type, or variable.
- Notation of the atomic time representation. This parameter is case sensitive.
Possible variants of atomic time notation:
- y refers to the year in number format.
- M refers to the month in number notation.
- d refers to the number of the month.
- wd refers to the day of the week: Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday.
- h refers to the hour in 24-hour format.
- m refers to the minutes.
- s refers to the seconds.
- (optional) Time zone notation. If this parameter is not specified, the time is calculated in UTC format.
Usage examples
extract_from_timestamp(Timestamp, 'wd')
extract_from_timestamp(Timestamp, 'h')
extract_from_timestamp($otherVariable, 'h')
extract_from_timestamp(Timestamp, 'h', 'Europe/Moscow')
"parse_timestamp" function
Converts the time from RFC3339 format (for example, "2022-05-24 00:00:00", "2022-05-24 00:00:00+0300) to epoch format.
Usage examples |
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"format_timestamp" function
Converts the time from epoch format to RFC3339 format.
The parameters must be specified in the following sequence:
- Event field of the timestamp type, or variable.
- Time format notation: RFC3339.
- (optional) Time zone notation. If this parameter is not specified, the time is calculated in UTC format.
Usage examples
format_timestamp(Timestamp, 'RFC3339')
format_timestamp($otherVariable, 'RFC3339')
format_timestamp(Timestamp, 'RFC3339', 'Europe/Moscow')
"truncate_timestamp" function
Rounds the time in epoch format. After rounding, the time is returned in epoch format. Time is rounded down.
The parameters must be specified in the following sequence:
- Event field of the timestamp type, or variable.
- Rounding parameter:
- 1s rounds to the nearest second.
- 1m rounds to the nearest minute.
- 1h rounds to the nearest hour.
- 24h rounds to the nearest day.
- (optional) Time zone notation. If this parameter is not specified, the time is calculated in UTC format.
Usage examples
Examples of rounded values
Usage result
truncate_timestamp(Timestamp, '1m')
1654631774175 (7 June 2022, 19:56:14.175)
1654631760000 (7 June 2022, 19:56:00)
truncate_timestamp($otherVariable, '1h')
1654631774175 (7 June 2022, 19:56:14.175)
1654628400000 (7 June 2022, 19:00:00)
truncate_timestamp(Timestamp, '24h', 'Europe/Moscow')
1654631774175 (7 June 2022, 19:56:14.175)
1654560000000 (7 June 2022, 0:00:00)
"time_diff" function
Gets the time interval between two timestamps in epoch format.
The parameters must be specified in the following sequence:
- Interval end time. Event field of the timestamp type, or variable.
- Interval start time. Event field of the timestamp type, or variable.
- Time interval notation:
- ms refers to milliseconds.
- s refers to seconds.
- m refers to minutes.
- h refers to hours.
- d refers to days.
Usage examples
time_diff(EndTime, StartTime, 's')
time_diff($otherVariable, Timestamp, 'h')
time_diff(Timestamp, DeviceReceiptTime, 'd')
Mathematical operations
These are comprised of basic mathematical operations and functions.
Basic mathematical operations
Supported for integer and float fields of the extended event schema.
Operations:
- Addition
- Subtraction
- Multiplication
- Division
- Modulo division
Parentheses determine the sequence of actions
Available arguments:
- Numeric event fields
- Numeric variables
- Real numbers
When modulo dividing, only natural numbers can be used as arguments.
Usage constraints:
- Division by zero returns zero.
- Mathematical operations between numbers and strings return zero.
- Integers resulting from operations are returned without a dot.
Usage examples
(Type=3; otherVariable=2; Message=text)
Usage result
Type + 1
4
$otherVariable - Type
-1
2 * 2.5
5
2 / 0
0
Type * Message
0
(Type + 2) * 2
10
Type % $otherVariable
1
"round" function
Rounds numbers. Supported for integer and float fields of the extended event schema.
Available arguments:
- Numeric event fields
- Numeric variables
- Numeric constants
Usage examples
(DeviceCustomFloatingPoint1=7.75; DeviceCustomFloatingPoint2=7.5 otherVariable=7.2)
Usage result
round(DeviceCustomFloatingPoint1)
8
round(DeviceCustomFloatingPoint2)
8
round($otherVariable)
7
"ceil" function
Rounds up numbers. Supported for integer and float fields of the extended event schema.
Available arguments:
- Numeric event fields
- Numeric variables
- Numeric constants
Usage examples
(DeviceCustomFloatingPoint1=7.15; otherVariable=8.2)
Usage result
ceil(DeviceCustomFloatingPoint1)
8
ceil($otherVariable)
9
"floor" function
Rounds down numbers. Supported for integer and float fields of the extended event schema.
Available arguments:
- Numeric event fields
- Numeric variables
- Numeric constants
Usage examples
(DeviceCustomFloatingPoint1=7.15; otherVariable=8.2)
Usage result
floor(DeviceCustomFloatingPoint1)
7
floor($otherVariable)
8
"abs" function
Gets the modulus of a number. Supported for integer and float fields of the extended event schema.
Available arguments:
- Numeric event fields
- Numeric variables
- Numeric constants
Usage examples
(DeviceCustomNumber1=-7; otherVariable=-2)
Usage result
abs(DeviceCustomFloatingPoint1)
7
abs($otherVariable)
2
"pow" function
Exponentiates a number. Supported for integer and float fields of the extended event schema.
The parameters must be specified in the following sequence:
- Base — real numbers.
- Power — natural numbers.
Available arguments:
- Numeric event fields
- Numeric variables
- Numeric constants
Usage examples
pow(DeviceCustomNumber1, DeviceCustomNumber2)
pow($otherVariable, DeviceCustomNumber1)
"str_join" function
Join multiple strings into one using a separator. Supported for integer and float fields of the extended event schema.
The parameters must be specified in the following sequence:
- Separator. String.
- String1, string2, stringN. At least 2 expressions.
Usage examples
Usage result
str_join('|', to_lower(Name), to_upper(Name), Name)
String.
"conditional" function
Get one value if a condition is met and another value if the condition is not met. Supported for integer and float fields of the extended event schema.
The parameters must be specified in the following sequence:
- Condition. String. The syntax is similar to the conditions of the Where statement in SQL. You can use the functions of the KUMA variables and references to other variables in a condition.
- The value if the condition is met. Expression.
- The value if the condition is not met. Expression.
Supported operators:
- AND
- OR
- NOT
- =
- !=
- <
- <=
- >
- >=
- LIKE (RE2 regular expression is used, rather than an SQL expression)
- ILIKE (RE2 regular expression is used, rather than an SQL expression)
- BETWEEN
- IN
- IS NULL (check for an empty value, such as 0 or an empty string)
Usage examples (the value depends on arguments 2 and 3)
conditional('SourceUserName = \\'root\\' AND DestinationUserName = SourceUserName', 'match', 'no match')
conditional(`DestinationUserName ILIKE 'svc_.*'`, 'match', 'no match')
conditional(`DestinationUserName NOT LIKE 'svc_.*'`, 'match', 'no match')
Operations for extended event schema fields
For extended event schema fields of the "string" type, the following kinds of operations are supported:
- "len" function
- "to_lower" function
- "to_upper" function
- "append" function
- "prepend" function
- "substring" function
- "tr" function
- "replace" function
- "regexp_replace" function
- "regexp_capture" function
For extended event schema fields of the integer or float type, the following kinds of mathematical operations are supported:
- Basic mathematical operations:
- "round" function
- "ceil" function
- "floor" function
- "abs" function
- "pow" function
- "str_join" function
- "conditional" function
For extended event schema fields of the "array of numbers", "array of floats", and "array of strings" types, the following kinds of mathematical operations are supported:
- item(SA.someStringArray, i) — gets the i-th element of the someStringArray[i] field.
- SA.someStringArray , returns ["string1", "string2", "string1"] — gets the array of values from the someStringArray field.
- len(SA.someStringArray) — gets the number of elements in the someStringArray array.
- distinct_items(SA.someStringArray), returns ["string1", "string2"] — gets unique elements from the someStringArray array.
- to_string(SA.someStringArray) — generates a TSV string from the array.
- sort_items(<type>.someStringArray); instead of <type>, you must specify the array type: 'sa' for an array of strings, 'fa' for an array of floats, 'na' for an array of integers. Example: sort_items (SA.StringArray, DESC)
For fields of the "array of integers" and "array of floats" types, the following functions are supported:
• math_min — returns the minimum element of an array. Example: math_min(NA.NumberArray), math_min(FA.FloatArray)
• math_max — returns the maximum element of an array. Example: math_max(NA.NumberArray), math_max(FA.FloatArray)
• math_avg — returns the average value of an array. Example: math_avg(NA.NumberArray), math_avg(FA.FloatArray)
Page topDeclaring variables
To declare variables, they must be added to a correlator or correlation rule.
To add a global variable to an existing correlator:
- In the KUMA console, under Resources → Correlators, select the resource set of the relevant correlator.
The Correlator Installation Wizard opens.
- Select the Global variables step of the Installation Wizard.
- click the Add variable button and specify the following parameters:
- In the Variable window, enter the name of the variable.
- In the Value window, enter the variable function.
Multiple variables can be added. Added variables can be edited or deleted by using the
icon.
- Select the Setup validation step of the Installation Wizard and click Save.
A global variable is added to the correlator. It can be queried like an event field by inserting the $ character in front of the variable name. The variable will be used for correlation after restarting the correlator service.
To add a local variable to an existing correlation rule:
- In the KUMA console, under Resources → Correlation rules, select the relevant correlation rule.
The correlation rule settings window opens. The parameters of a correlation rule can also be opened from the correlator to which it was added by proceeding to the Correlation step of the Installation Wizard.
- Open the Selectors tab.
- In the selector, open the Local variables tab, click the Add variable button and specify the following parameters:
- In the Variable window, enter the name of the variable.
- In the Value window, enter the variable function.
Multiple variables can be added. Added variables can be edited or deleted by using the
icon.
For standard correlation rules, repeat this step for each selector in which you want to declare variables.
- Click Save.
The local variable is added to the correlation rule. It can be queried like an event field by inserting the $ character in front of the variable name. The variable will be used for correlation after restarting the correlator service.
Added variables can be edited or deleted. If the correlation rule queries an undeclared variable (for example, if its name has been changed), an empty string is returned.
If you change the name of a variable, you will need to manually change the name of this variable in all correlation rules where you have used it.
Page topPredefined correlation rules
The OSMP distribution kit includes correlation rules listed in the table below.
Predefined correlation rules
Correlation rule name |
Description |
[OOTB] KATA alert |
Used for enriching KATA events. |
[OOTB] Successful Bruteforce |
Triggers when a successful authentication attempt is detected after multiple unsuccessful authentication attempts. This rule works based on the events of the sshd daemon. |
[OOTB][AD] Account created and deleted within a short period of time |
Detects instances of creation and subsequent deletion of accounts on Microsoft Windows hosts. |
[OOTB][AD] An account failed to log on from different hosts |
Detects multiple unsuccessful attempts to authenticate on different hosts. |
[OOTB][AD] Granted TGS without TGT (Golden Ticket) |
Detects suspected "Golden Ticket" type attacks. This rule works based on Microsoft Windows events. |
[OOTB][AD][Technical] 4768. TGT Requested |
The technical rule used to populate the active list is [OOTB][AD] List of requested TGT. EventID 4768. This rule works based on Microsoft Windows events. |
[OOTB][AD] Membership of sensitive group was modified |
Works based on Microsoft Windows events. |
[OOTB][AD] Multiple accounts failed to log on from the same host |
Triggers after multiple failed authentication attempts are detected on the same host from different accounts. |
[OOTB][AD] Possible Kerberoasting attack |
Detects suspected "Kerberoasting" type attacks. This rule works based on Microsoft Windows events. |
[OOTB][AD] Successful authentication with the same account on multiple hosts |
Detects connections to different hosts under the same account. This rule works based on Microsoft Windows events. |
[OOTB][AD] The account added and deleted from the group in a short period of time |
Detects the addition of a user to a group and subsequent removal. This rule works based on Microsoft Windows events. |
[OOTB][Net] Possible port scan |
Detects suspected port scans. This rule works based on Netflow, Ipfix events. |