Atatus Cloud SIEM uses a compact filter language (DSL) to select security events. You use the same syntax when writing the queries in a detection rule and when searching the signals list.

This page is the complete reference for that syntax.


Basic structure

A filter is one or more field:value predicates. Multiple predicates are combined with AND by default:

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source:okta AND eventAction:user.session.start AND eventOutcome:SUCCESS

Field names must be valid for the data source you are querying. In the rule builder, field auto-complete is scoped to the rule's first data source, which helps you pick valid names.


Operators

Syntax Meaning Example
key:value Exact match on a single value eventAction:ConsoleLogin
key:(A OR B) Match any of several values eventAction:(AttachUserPolicy OR AttachRolePolicy)
key:[N TO M] Range match (inclusive) statusCode:[400 TO 499]
key:>N key:>=N Greater than / greater than or equal bytesOut:>1000000
key:<N key:<=N Less than / less than or equal responseTime:<50
key:*value* Wildcard / glob match processName:*svchost*
key:* Field exists / matches anything userName:*
"phrase query" Match an exact phrase message:"permission denied"
-key:value Negate a predicate -eventOutcome:SUCCESS
NOT key:value Alternative negation syntax NOT status:closed
(expr) Group expressions (eventAction:login OR eventAction:logout)

Logical operators

  • AND joins predicates that must all match. It is implied between predicates, so you can usually omit it.
  • OR matches when any predicate matches. Wrap OR groups in parentheses.
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source:cloudtrail AND (eventAction:AttachUserPolicy OR eventAction:AttachRolePolicy)

CIDR and IP ranges

You can match IP addresses using CIDR notation or numeric ranges:

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sourceIP:10.0.0.0/8 OR sourceIP:[192.168.0.0 TO 192.168.255.255]

Visual builder vs. DSL mode

In the rule builder, the Filter input offers two modes:

  • Visual builder — Build AND/OR chains row by row, picking a field, an operator, and a value with auto-complete. This covers most common filters.
  • DSL mode — A text box for the full syntax above. Switch to DSL mode when you need negation, ranges ([N TO M]), CIDR matching, deeply nested groups, or a top-level OR.

Filters written in either mode produce the same query.


Examples

Detect AWS root console logins:

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source:cloudtrail AND eventAction:ConsoleLogin AND cloudIdentityType:Root AND eventOutcome:Success

Detect privileged container creation in Kubernetes:

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source:kubernetes AND k8sResource:pods AND @requestObject.spec.containers.securityContext.privileged:true

Detect failed SSH authentication:

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source:runtime-security-agent AND auditdMessageType:USER_AUTH AND auditdResult:fail

Tips

  • Balance your delimiters. Parentheses (), brackets [], and quotes " must be balanced, or the filter is rejected.
  • Do not leave a value empty after a colon — eventAction: is invalid.
  • Use known field names. Unknown fields are flagged with a suggestion. Let the auto-complete guide you to canonical field names.
  • Combine with group-by. Filters select events; the rule's Group by and Aggregation settings decide how those events are counted. See Creating Custom Detection Rules.

Next steps