AWS STS AssumeRole Misuse
This rule identifies suspicious usage of the AWS Security Token Service (STS) `AssumeRole` API call. Specifically, it looks for instances where the `userIdentity.type` is `AssumedRole` and the `userIdentity.sessionContext.sessionIssuer.type` is `Role`. This pattern indicates that an AWS role is being assumed by another role, which could be a legitimate administrative action but also a technique used by attackers for lateral movement and privilege escalation within an AWS environment. Attackers might use `AssumeRole` to switch to roles with higher privileges or to move between different accounts or services after gaining initial access.
Sigma
