Serverless
Where this stands
No Sigma rule can address this — the telemetry MITRE names has no Sigma logsource behind it.
This happens on infrastructure you do not own, so it never reaches your logs. MITRE's own guidance is internet scanning and threat intelligence, not log analysis.
What the technique is
Adversaries may compromise serverless cloud infrastructure, such as Cloudflare Workers, AWS Lambda functions, or Google Apps Scripts, that can be used during targeting. By utilizing serverless infrastructure, adversaries can make it more difficult to attribute infrastructure used during operations back to them. Once compromised, the serverless runtime environment can be leveraged to either respond directly to infected machines or to Proxy traffic to an adversary-owned command and control server. As traffic generated by these functions will appear to come from subdomains of common cloud providers, it may be difficult to distinguish from ordinary traffic to these providers - making it easier to Hide Infrastructure.
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN1996
Once adversaries leverage serverless functions as infrastructure (ex: for command and control), it may be possible to look for unique characteristics associated with adversary software, if known. Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on related stages of the adversary lifecycle.
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.