Windows: Remote Task Creation via ATSVC Named Pipe

Rule ID

PH_Rule_SIGMA_17

Default Status

Enabled

Description

Detects remote task creation via at.exe or API interacting with ATSVC namedpipe. This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/security/win_security_atsvc_task.yml

Severity

MITRE ATT&CK® Tactics

Execution

Execution consists of techniques that result in adversary-controlled code running on a local or remote system. Techniques that run malicious code are often paired with techniques from all other tactics to achieve broader goals, like exploring a network or stealing data. For example, an adversary might use a remote access tool to run a PowerShell script that does Remote System Discovery.

https://attack.mitre.org/tactics/TA0002

MITRE ATT&CK® Techniques

T1053.002

Scheduled Task/Job: At (Windows)

Adversaries may abuse the at.exe utility to perform task scheduling for initial or recurring execution of malicious code. The at.exe command line utility has been deprecated in current versions of Windows in favor of schtasks.

https://attack.mitre.org/techniques/T1053/002

Impacts

Server

Data Source

Windows Security Log via OMI or FortiSIEM Agent

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.

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="Win-Security-5145" AND fileName="\\\\*\\IPC$" AND targetName="atsvc" AND osObjAccessType REGEXP ".*WriteData.*"

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

fileName,hostName,osObjAccessType,targetName

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

fileName = Filter.fileName,
hostName = Filter.hostName,
osObjAccessType = Filter.osObjAccessType,
targetName = Filter.targetName

FortiSIEM Rules