Local 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:

  1. Add a local variable to the rule.
  2. 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 "$" character.
  3. In the Correlation rules window, go to the Actions tab, and under Enrichment, in the Source kind drop-down list, select Event.
  4. From the Target field drop-down list, select the KUMA event field to which you want to pass the value of the local variable.
  5. From the Source field drop-down list, select a local variable. Prefix the local variable name with a "$" character.
  6. Specify the remaining rule settings.
  7. Click Save.
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