Suspicious SeIncreaseBasePriorityPrivilege Use
Identifies attempts to use the SeIncreaseBasePriorityPrivilege privilege by an unusual process. This could be related to hijack execution flow of a process via threats priority manipulation.
Rule type: query
Rule indices:
- logs-system.security*
- logs-windows.forwarded*
- winlogbeat-*
Rule Severity: high
Risk Score: 73
Runs every:
Searches indices from: now-9m
Maximum alerts per execution: ?
References:
- https://github.com/Octoberfest7/ThreadCPUAssignment_POC/tree/main
- https://x.com/sixtyvividtails/status/1970721197617717483
- https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-10/security/threat-protection/auditing/event-4674
Tags:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Privilege Escalation
- Data Source: Windows Security Event Logs
- Resources: Investigation Guide
Version: ?
Rule authors:
- Elastic
Rule license: Elastic License v2
Ensure advanced audit policies for Windows are enabled, specifically: Audit Sensitive Privilege Use Event ID 4674 (An operation was attempted on a privileged object.)
Computer Configuration >
Policies >
Windows Settings >
Security Settings >
Advanced Audit Policies Configuration >
Audit Policies >
Privilege Use >
Audit Sensitive Privilege Use (Success)
SeIncreaseBasePriorityPrivilege allows to increase the priority of processes running on the system so that the CPU scheduler allows them to pre-empt other lower priority processes when the higher priority process has something to do.
- Review the process.executable reputation and it's execution chain.
- Investiguate if the SubjectUserName is expected to perform this action.
- Correlate the event with other security alerts or logs to identify any patterns or additional suspicious activities that might suggest a broader attack campaign.
- Check the agent health status and verify if there is any tampering with endpoint security processes.
- Administrative tasks involving legitimate CPU scheduling priority changes.
- Immediately isolate the affected machine from the network to prevent further unauthorized access or lateral movement within the domain.
- Terminate the processes involved in the execution chain.
- Escalate the incident to the security operations center (SOC) or incident response team for further investigation and to ensure comprehensive remediation efforts are undertaken.
event.category:iam and event.code:"4674" and
winlog.event_data.PrivilegeList:"SeIncreaseBasePriorityPrivilege" and event.outcome:"success" and
winlog.event_data.AccessMask:"512" and not winlog.event_data.SubjectUserSid:("S-1-5-18" or "S-1-5-19" or "S-1-5-20")
Framework: MITRE ATT&CK
Tactic:
- Name: Privilege Escalation
- Id: TA0004
- Reference URL: https://attack.mitre.org/tactics/TA0004/
Technique:
- Name: Access Token Manipulation
- Id: T1134
- Reference URL: https://attack.mitre.org/techniques/T1134/