AWS Bedrock API Key Phantom User Activity Outside Bedrock

Description

Identifies an Amazon Bedrock API key phantom user (an IAM user whose name starts with "BedrockAPIKey-") acting as the caller of a non-Bedrock API request, such as IAM, STS, EC2, VPC, or KMS calls. These users are provisioned by AWS to back a Bedrock bearer token and carry the AmazonBedrockLimitedAccess managed policy, which also grants IAM, VPC, and KMS reconnaissance. A phantom user performing activity outside of Bedrock indicates its credentials are being used beyond their intended scope, which is the privilege-escalation path realized: an attacker who created standard IAM access keys for the phantom user is now using them for reconnaissance or lateral movement outside the Bedrock authentication boundary.

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 ATT&CK technique it maps to.
Log source category: event_index

Known benign triggers

Automation or SDK tooling configured with a Bedrock API key may call non-Bedrock APIs for benign credential validation. Ubiquitous no-op STS identity calls (GetCallerIdentity, GetSessionToken, GetAccessKeyInfo) are excluded; other non-Bedrock activity by a BedrockAPIKey-* principal — recon, privilege escalation, lateral movement, or exfiltration — is unexpected for an inference-only key. Confirm the key and source in "source.ip"/"user_agent.original" are sanctioned.

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/bedrock/latest/userguide/api-keys.html	Product documentation	3
www.beyondtrust.com/blog/entry/aws-bedrock-security-api-keys	Unclassified	3
www.beyondtrust.com/blog/entry/aws-bedrock-security-guide-api-keys-detection-response	Unclassified	4

Detection rules

AWS Bedrock API Key Phantom User Activity Outside Bedrock

Description

Detection logic

Detection requirements

Known benign triggers

MITRE ATT&CK mappings

References

From the source

Licence

Authorship

Detection rules