PH_Rule_SIGMA_431
Enabled
Detects an interactive AT job, which may be used as a form of privilege escalation. This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_at_interactive_execution.yml
7
Security
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/TA0002T1053.002
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/T1053/002Server
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-1-Create-Process" AND procName REGEXP "\\at\.exe$" AND command REGEXP ".*interactive.*"
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
command,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
command = Filter.command,
hostName = Filter.hostName,
procName = Filter.procName