Uncommon Windows process Created

Rule ID

PH_Rule_LT_1

Default Status

Disabled

Description

Detects uncommon windows process creation that has not been seen in the CommonWindowsProcess lookup table. By default, the lookup table captures results for 1 day.

Severity

MITRE ATT&CK® Tactics

Defense Evasion

Defense Evasion consists of techniques that adversaries use to avoid detection throughout their compromise. Techniques used for defense evasion include uninstalling/disabling security software or obfuscating/encrypting data and scripts. Adversaries also leverage and abuse trusted processes to hide and masquerade their malware. Other tactics’ techniques are cross-listed here when those techniques include the added benefit of subverting defenses.

https://attack.mitre.org/tactics/TA0005

MITRE ATT&CK® Techniques

T1484.001

Domain Policy Modification: Group Policy Modification

Adversaries may modify Group Policy Objects (GPOs) to subvert the intended discretionary access controls for a domain, usually with the intention of escalating privileges on the domain. Group policy allows for centralized management of user and computer settings in Active Directory (AD). GPOs are containers for group policy settings made up of files stored within a predicable network path \\<DOMAIN>\SYSVOL\<DOMAIN>\Policies\.(Citation: TechNet Group Policy Basics)(Citation: ADSecurity GPO Persistence 2016)

https://attack.mitre.org/techniques/T1484/001

Impacts

Server

Data Source

Windows Sysmon via FortiSIEM Agent

Detection

Correlation Using Lookup Table

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.

300 seconds

Trigger Conditions

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

Filter

SubPattern Definitions

SubPattern Name: Filter

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 = "PH_OSQUERY_WIN_PARENT_CHILD_PROCESS" AND LookupTableHas(WinProcessOSQuery_0,procName,filePath,parentProcName,hashSHA256) = 0

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

reptDevName,procName,filePath,parentProcName,hashSHA256

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 = Filter.reptDevName,
 procName = Filter.procName,
 filePath = Filter.filePath,
 parentProcName = Filter.parentProcName,
 hashSHA256=Filter.hashSHA256

FortiSIEM Rules