FortiSIEM Rules

UEBA Policy detects antivirus not started

Rule ID

PH_Rule_UEBA_37

Default Status

Disabled

Description

FortiSIEM UEBA Policy detects antivirus not started when machine switched on user will replace ccsvchst.exe

Severity

7

Category

Security

MITRE ATT&CK® Tactics

UEBA

MITRE ATT&CK® Techniques

No Technique Specified

Impacts

Application

Data Source

Windows via FortiSIEM Agent with UEBA turned on

Detection

Correlation

Remediation Guidance

No remediation guidance specified

Time Window

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

600 seconds

Trigger Conditions

If the following defined pattern/s occur within a 600 second time window.

UEBA_MachineOn FOLLOWED_BY UEBA_AV_NotStart

Global Constraint

This defines how two or more distinct events are related in a time-series based action. e.g. An event occurs followed by another event if the source IP, user, and messageId are the same

UEBA_MachineOn.hostName = UEBA_AV_NotStart.hostName AND
      UEBA_MachineOn.procName = UEBA_AV_NotStart.procName

SubPattern Definitions

SubPattern Name: UEBA_MachineOn

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

eventType = "FINS-Windows-machine-on"  AND user NOT REGEXP ".*\$$|dwn-.*|dwm-.*|umfd-.*|.*SYSTEM.*|.*ANONYMOUS.*"

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

hostName,domain,user,procName,activityName,resourceName

Aggregate Constraint

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

COUNT(*) >= 1
Operator Rank: 0 Operator Type: FOLLOWED_BY

This operator defines the logic condition relating to the prior event subpattern clause and the following event subpattern clause

SubPattern Name: UEBA_AV_NotStart

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

eventType IN ("FINS-Windows-new-process-created", "FINS-Windows-machine-off") AND (procName IS NULL OR procName = "ccsvchst.exe")  AND user NOT REGEXP ".*\$$|dwn-.*|dwm-.*|umfd-.*|.*SYSTEM.*|.*ANONYMOUS.*"

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

hostName,domain,user,procName,activityName,resourceName

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 = UEBA_MachineOn.hostName,
 domain = UEBA_MachineOn.domain,
 user = UEBA_MachineOn.user,
 procName = UEBA_MachineOn.procName,
 activityName = UEBA_MachineOn.activityName,
 resourceName = UEBA_MachineOn.resourceName