PH_Rule_SIGMA_1125
Enabled
Detects known malicious service installs that appear in cases in which a Cobalt Strike beacon elevates privileges or lateral movement. 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_cobaltstrike_service_installs.yml
9
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/TA0002T1569.002
System Services: Service Execution
Adversaries may abuse the Windows service control manager to execute malicious commands or payloads. The Windows service control manager is an interface to manage and manipulate services. The service control manager is accessible to users via GUI components as well as system utilities such as sc.exe. PsExec can also be used to execute commands or payloads via a temporary Windows service created through the service control manager API. Adversaries may execute malicious content by either executing a new or modified service. This technique is the execution used in conjunction with Windows Service during service persistence or privilege escalation.
https://attack.mitre.org/techniques/T1569/002Server
Windows System Log via OMI or FortiSIEM Agent
Correlation
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.
If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.
300 secondsIf the following defined pattern/s occur within a 300 second time window.
FilterThis 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-System-Service-Control-Manager-7045") AND ((serviceFileName REGEXP ".*ADMIN\$.*" AND serviceFileName REGEXP ".*\.exe.*") OR (serviceFileName REGEXP ".*%COMSPEC%.*" AND serviceFileName REGEXP ".*start.*" AND serviceFileName REGEXP ".*powershell.*") OR serviceFileName REGEXP ".*powershell -nop -w hidden -encodedcommand.*" OR serviceFileName REGEXP ".*JRVggKE5ldy1PYmplY3QgTmV0LldlYmNsaWVudCkuRG93bmxvYWRTdHJpbmcoJ2h0dHA6Ly8xMjcuMC4wLjE6.*|.*SUVYIChOZXctT2JqZWN0IE5ldC5XZWJjbGllbnQpLkRvd25sb2FkU3RyaW5nKCdodHRwOi8vMTI3LjAuMC4xO.*|.*lFWCAoTmV3LU9iamVjdCBOZXQuV2ViY2xpZW50KS5Eb3dubG9hZFN0cmluZygnaHR0cDovLzEyNy4wLjAuMT.*")This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
hostName,serviceFileNameThis is most typically a numerical constraint that defines when the rule should trigger an incident
COUNT(*) >= 1This 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