Field replacement syntax in correlation rules

Learn more about how to use field replacement syntax when creating correlation rules.

When creating correlation rules, it's possible to use predefined values for different fields in the editor, such as Alert Name, Alert Description, and Drill-Down Query. These predefined values follow a certain syntax and are dependent on the Cortex Query Language (XQL) query for the correlation rule that you build in the XQL Search and Drill-Down Query areas in the editor. For example, if you define the Alert Name to be something, such as Alerts based on $agent_name, the XQL query defining the correlation rule must have the agent_name field defined in the logic of the query; otherwise, this field won't be replaced.

Standard field replacement

Syntax

$<field>

Example:

The following text is added to the Alert Description field in the correlation rule editor, which uses a regular field:

The user's registered email is: $Email

Example Results:

If the Email field is a saved value containing [e-mail], the output of the Alert Description is:

The user's registered email is: [e-mail]

Example:

The following text is added to the Alert Description field in the correlation rule editor, using an XDM field:

The user's registered email is: $xdm.email.recipient

Example Results:

If the xdm.email.recipient field is a saved value containing [e-mail], the output is:

The user's registered email is: [e-mail]

Keep in mind the following:

• <field> identifiers must consist exclusively of alphanumeric characters (a-z, A-Z, 0-9) and underscores (_).
• Cortex Data Model (XDM) fields can include dot (.) characters.
• While <field> identifiers can begin with a numeric character, the fields cannot be composed solely of numeric characters. For example, $123_data is permissible, whereas $456 is not.
• Text enclosed with double quotes ("<text>") is treated as a literal string and will not undergo field replacement.

  Example:

  The following text is added to the Alert Description field in the correlation rule editor:

  The user's registered email is: "$Email"

  Example Results:

  Since the syntax is invalid, it's ignored and the same text is displayed:

  The user's registered email is: "$Email"

Fields with special characters

When field names contain characters that are not permitted in the standard $<field> syntax, such as spaces, hyphens, or special symbols, the field name must be enclosed within backticks (``)

Syntax

$`<field>`

Example:

The following text is added to the Alert Description field in the correlation rule editor, using a field containing characters that are not permitted:

Report Title: $`Annual Sales Report - Q1 2025`

Example Results:

If the Annual Sales Report - Q1 2025 field is a saved value containing Executive Summary, the output is:

Report Title: Executive Summary