AWS Bedrock Claude excessive use of tokens
Detects identities generating anomalously large model responses relative to their own historical baseline. For each identity, computes the average, maximum, and standard deviation of output token counts across all…
Description
Detects identities generating anomalously large model responses relative to their own historical baseline. For each identity, computes the average, maximum, and standard deviation of output token counts across all invocations, then flags any identity whose single largest response exceeds two standard deviations above their own mean. A statistically significant output spike from a single identity may indicate bulk data extraction, successful prompt injection producing verbose output, or a runaway agentic loop hitting context limits.
Detection logic
Detection requirements
- Platform
- LinuxmacOSWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- aws_bedrock_claude
Known benign triggers
- This detection may produce false positives for identities with low invocation history, legitimate large document summarization tasks, or automated pipeline sessions with naturally variable output token counts.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| aws.amazon.com/blogs/apn/unlocking-the-power-of-splunk-with-amazon-bedrock-an-agentic-ai-approach-to-build-customized-splunk-assistants-using-bedrock-agents/ | 7 |
| docs.aws.amazon.com/bedrock/latest/userguide/model-invocation-logging.html | 8from 2 sources |
| help.splunk.com/en/splunk-observability-cloud/observability-for-ai/splunk-ai-infrastructure-monitoring/set-up-ai-infrastructure-monitoring/amazon-bedrock | 7 |
| research.splunk.com/stories/aws_bedrock_security/ | 7 |
From the source
- At source
- Open at source
- Upstream identifier
- a839a6f7-aaac-438b-9d99-be0b49481e17
- Tagged by the source as
- Suspicious AWS Bedrock Claude ActivitiesWeb ApplicationapplicationSplunk CloudSplunk EnterpriseSplunk Enterprise Securityendpoint
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Aug 26, 2026
- Version
- 1