PH_Rule_SIGMA_329
Enabled
Detects file writes of WMI script event consumer. This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/file/file_event/file_event_win_wmi_persistence_script_event_consumer_write.yml
7
Security
Persistence
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.
https://attack.mitre.org/tactics/TA0003T1546.003
Event Triggered Execution: Windows Management Instrumentation Event Subscription
Adversaries may establish persistence and elevate privileges by executing malicious content triggered by a Windows Management Instrumentation (WMI) event subscription. Adversaries may use the capabilities of WMI to subscribe to an event and execute arbitrary code when that event occurs, providing persistence on a system. Adversaries may also compile WMI scripts into Windows Management Object (MOF) files (.mof extension) that can be used to create a malicious subscription.
https://attack.mitre.org/techniques/T1546/003Server
Windows Sysmon via FortiSIEM Agent
Correlation
No remediation guidance specified
If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.
300 seconds
If the following defined pattern/s occur within a 300 second time window.
Filter
This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.
This is the query logic that matches incoming events
eventType="Win-Sysmon-11-FileCreate" AND procName="C:\\WINDOWS\\system32\\wbem\\scrcons.exe"
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
hostName,procName
This is most typically a numerical constraint that defines when the rule should trigger an incident
COUNT(*) >= 1
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 = Filter.hostName,
procName = Filter.procName