Windows: Meterpreter or Cobalt Strike Getsystem Service Installation - System

Rule ID

PH_Rule_SIGMA_40

Default Status

Enabled

Description

Detects the use of getsystem Meterpreter/Cobalt Strike command by detecting a specific service installation. Cobalt Strike (https://www.cobaltstrike.com/) is an adversary simulation tool with a post-exploitation agent and covert channels to emulate a quiet long-term embedded actor in your network. It uses Process injection, a defense evasion technique that runs custom code within the address space of another process, thereby avoiding detection. This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/system/service_control_manager/win_system_meterpreter_or_cobaltstrike_getsystem_service_installation.yml

Severity

9High

Category

Security

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.

MITRE ATT&CK® Techniques

T1134.002

Access Token Manipulation: Create Process with Token

Adversaries may create a new process with a duplicated token to escalate privileges and bypass access controls. An adversary can duplicate a desired access token with "DuplicateToken(Ex)" and use it with "CreateProcessWithTokenW" to create a new process running under the security context of the impersonated user. This is useful for creating a new process under the security context of a different user.

Impacts

Server

Data Source

Windows System Log via OMI or FortiSIEM Agent

Detection

Correlation

Remediation Guidance

Cobalt Strike / Meterpreter are intended to be used by penetration testers and security red teams to simulate a real cyberthreat. Investigate whether the user needs to really run Cobalt Strike or Meterpreter. Investigate what other incidents are occurring on that host during that time frame. If necessary, rebuild the host from a known, good source and have the user change their password.

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

(eventType="Win-System-Service-Control-Manager-7045") AND ((serviceFileName REGEXP ".*cmd.*" AND serviceFileName REGEXP ".*/c.*" AND serviceFileName REGEXP ".*echo.*" AND serviceFileName REGEXP ".*\\pipe\\.*") OR (serviceFileName REGEXP ".*%COMSPEC%.*" AND serviceFileName REGEXP ".*/c.*" AND serviceFileName REGEXP ".*echo.*" AND serviceFileName REGEXP ".*\\pipe\\.*") OR (serviceFileName REGEXP ".*cmd\.exe.*" AND serviceFileName REGEXP ".*/c.*" AND serviceFileName REGEXP ".*echo.*" AND serviceFileName REGEXP ".*\\pipe\\.*") OR (serviceFileName REGEXP ".*rundll32.*" AND serviceFileName REGEXP ".*\.dll,a.*" AND serviceFileName REGEXP ".*/p:.*") OR serviceFileName REGEXP "^\\\\127\.0\.0\.1\\ADMIN\$\\")

hostName,serviceFileName

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.hostName,
serviceFileName = Filter.serviceFileName