FortiSIEM Rules

Domain Controller User or Group Modification

Rule ID


Default Status



Detects user/group configuration in a domain controller. This rule would trigger on all changes made by any person. To prevent false positives, a restriction on the user attribute should be made by excluding the domain administrators.







Persistence consists of techniques that adversaries use to keep access to systems across restarts, changed credentials, and other interruptions that could cut off their access. Techniques used for persistence include any access, action, or configuration changes that let them maintain their foothold on systems, such as replacing or hijacking legitimate code or adding startup code.

MITRE ATT&CK® Techniques


Account Manipulation: Additional Cloud Credentials

Adversaries may add adversary-controlled credentials for Azure Service Principals in addition to existing legitimate credentials to maintain persistent access to victim Azure accounts. Azure Service Principals support both password and certificate credentials. With sufficient permissions, there are a variety of ways to add credentials including the Azure Portal, Azure command line interface, and Azure powershell.



Data Source

Windows Security Log via OMI or FortiSIEM Agent



Remediation Guidance

Make sure it is an authorized change

Time Window

If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.

300 seconds

Trigger Conditions

If the following defined pattern/s occur within a 300 second time window.


SubPattern Definitions

SubPattern Name: DCUserGrpChange

This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.

SubPattern Query

This is the query logic that matches incoming events

reptDevIpAddr IN (Group@PH_SYS_APP_DOMAIN_CONTROLLER)  AND  eventType IN ( Group@PH_SYS_EVENT_AccountChanged)

Group by Attributes

This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID


Aggregate Constraint

This is most typically a numerical constraint that defines when the rule should trigger an incident

COUNT(*) >= 1

Incident Attribute Mapping

This section defines which fields in matching raw events should be mapped to the incident attributes in the resulting incident.

The available raw event attributes to map are limited to the group by attributes and the aggregate event constraint fields for each subpattern

 hostName = DCUserGrpChange.reptDevName,
 user = DCUserGrpChange.user,
 computer =,
 domain = DCUserGrpChange.domain,
 targetUser = DCUserGrpChange.targetUser,
 targetDomain = DCUserGrpChange.targetDomain