AWS EC2 Stop, Start, and User Data Modification Correlation

Description

Identifies a short sequence of EC2 management APIs against the same instance that is consistent with modifying instance user data and forcing it to run on the next boot: `ModifyInstanceAttribute` with user data, followed by stop and start. Adversaries may update `userData` and cycle instance state so malicious scripts execute as root on Linux or as the system context on Windows. This rule correlates successful `StopInstances`, `StartInstances`, and `ModifyInstanceAttribute` events that reference `userData` within a five-minute window, grouped by instance, `user.name`, account, source IP, and user agent. A hit requires exactly three distinct API names in that bucket.

Detection logic

Its licence does not clear it for publishing here

Sunturai publishes a detection's own text where the licence it arrived under has been reviewed and permits it, and Elastic License 2.0 has not. The query as its source wrote it, its canonical form and the hash that pins this revision are in the workspace record.

Detection requirements

Platform: Containers ESXi IaaS Identity Provider Linux macOS Network Devices Office Suite SaaS Windows
The rule states no platform. This is derived from the 2 ATT&CK techniques it maps to.

Known benign triggers

Legitimate automation or administrators may change user data and restart instances during maintenance, image baking, or configuration fixes. Review the caller identity, change tickets, and whether `user_agent.original` and `source.ip` match known tooling and networks (the rule groups on both together with `user.name`).

References

Links the source published beside this detection. Reference is the link the source wrote, unmodified. Class is decided by this catalogue from the host and path, not stated by the source. Cited by counts published detections citing the same resource, including this one, and the sources beneath it count the repositories this catalogue ingests, which is not the same as independent research.
Reference	Class	Cited by
docs.aws.amazon.com/AWSEC2/latest/APIReference/API_ModifyInstanceAttribute.html	Product documentation	Only this detection cites it
hackingthe.cloud/aws/exploitation/local_ec2_priv_esc_through_user_data	Unclassified	2

Detection rules

AWS EC2 Stop, Start, and User Data Modification Correlation

Description

Detection logic

Detection requirements

Known benign triggers

MITRE ATT&CK mappings

References

From the source

Licence

Authorship

Detection rules