New GitHub Self Hosted Action Runner
Description
This rule detects the creation of a self-hosted Github runner from a first time seen user.name in the last 5 days. Adversaries may abuse self-hosted runners to execute workflow jobs on customer infrastructure.
Query · kuery
data_stream.dataset:"github.audit" and
event.category:"configuration" and
event.action: (
"repo.register_self_hosted_runner" or
"org.register_self_hosted_runner" or
"enterprise.register_self_hosted_runner"
)
Known false positives
- Authorized self-hosted GitHub actions runner.
Analyst notes
Investigating New GitHub Self Hosted Action Runner
Adversaries who gain the ability to modify or trigger workflows in a linked GitHub repository can execute arbitrary commands on the runner host.
Possible investigation steps
- Validate the user is authoried to perform this change
- Review the purpose of the self-hosted action runner and what actions will be executed.
- Verify if there is any adjascent sensitive file access or collection.
- Correlate with other alerts and investiguate if this activity is related to a supply chain attack.
False positive analysis
- Authorized github self-hosted actions runner.
Response and remediation
- Immediately isolate the affected system from the network to prevent further unauthorized command execution and potential lateral movement.
- Terminate any suspicious child processes that were initiated by the Github actions runner.
- Conduct a thorough review of the affected system's logs and configurations to identify any unauthorized changes or additional indicators of compromise.
- Restore the system from a known good backup if any unauthorized changes or malicious activities are confirmed.
- Implement application whitelisting to prevent unauthorized execution.
- Escalate the incident to the security operations center (SOC) or incident response team for further investigation and to assess the potential impact on the broader network.