AWS Bedrock Model Prompt or Completion Containing Credentials
Description
Identifies an Amazon Bedrock model invocation whose prompt or completion contains an AWS access key identifier (AKIA long-term or ASIA temporary/STS, followed by 16 characters), an Amazon Bedrock API key (ABSK bearer token), or a PEM private-key block. Credentials in the model input mean an application or user is sending secrets to the model, exposing them to invocation logging, the model provider, and prompt history; credentials in the model output mean the model is emitting secrets, which can result from training-data leakage, poisoned context, or a prompt-injection-driven exfiltration attempt. Either case is a credential-exposure event that warrants immediate rotation of the affected secret.
Query · esql
from logs-aws_bedrock.invocation-* metadata _id, _version, _index
| where event.action in ("ConverseStream", "Converse") AND
( gen_ai.prompt rlike """.*(AKIA|ASIA)[A-Z0-9]{16}.*"""
or gen_ai.completion rlike """.*(AKIA|ASIA)[A-Z0-9]{16}.*"""
or gen_ai.prompt rlike """.*-----BEGIN [A-Z ]*PRIVATE KEY-----.*"""
or gen_ai.completion rlike """.*-----BEGIN [A-Z ]*PRIVATE KEY-----.*"""
or gen_ai.prompt rlike """.*ABSK[A-Za-z0-9+/=]{20}.*"""
or gen_ai.completion rlike """.*ABSK[A-Za-z0-9+/=]{20}.*"""
or gen_ai.prompt rlike """.*gh[pousr]_[A-Za-z0-9]{36}.*"""
or gen_ai.completion rlike """.*gh[pousr]_[A-Za-z0-9]{36}.*"""
or gen_ai.prompt rlike """.*github_pat_[A-Za-z0-9_]+.*"""
or gen_ai.completion rlike """.*github_pat_[A-Za-z0-9_]+.*"""
or gen_ai.prompt rlike """.*glpat-[A-Za-z0-9_\\-]+.*"""
or gen_ai.completion rlike """.*glpat-[A-Za-z0-9_\\-]+.*""")
| keep _id, _version, _index, @timestamp, gen_ai.*, aws_bedrock.*, user.*, cloud.*, event.*
Implementation guide
This rule requires Amazon Bedrock model invocation logs ingested via the Elastic AWS Bedrock integration, with text data delivery enabled in the Bedrock model-invocation-logging configuration.
Known false positives
- Prompts or completions that reference example or documentation keys (for example the AWS sample access key ending in EXAMPLE) match the access-key pattern. Review the matched value in "gen_ai.prompt" or "gen_ai.completion" and confirm whether it is a live credential before responding.
Analyst notes
Investigating AWS Bedrock Model Prompt or Completion Containing Credentials
Bedrock model invocation logging records the full request and response of each InvokeModel/Converse call. This rule scans the decoded prompt and completion for live-credential patterns: AWS access key IDs (AKIA/ASIA followed by 16 characters) and PEM private-key headers. A credential in the prompt indicates secrets are being sent to the model (and persisted in logs and, for hosted models, to the provider); a credential in the completion indicates the model returned a secret, which is a sign of training-data or context leakage or a successful prompt-injection exfiltration.
Possible investigation steps
- Review the matched value in "gen_ai.prompt" and "gen_ai.completion" and confirm whether it is a live credential or an example/placeholder.
- Identify the caller in "user.id" and the model in "aws_bedrock.invocation.model_id", and determine which application generated the invocation.
- If the credential is in the completion, review the prompt for injection or data-exfiltration instructions and check the model's knowledge base or context sources.
- Determine the scope and privileges of the exposed credential to gauge impact.
False positive analysis
- Example or documentation keys (such as the AWS EXAMPLE key) match the pattern. Confirm the value is a real credential before escalating.
Response and remediation
- If the credential is live, rotate or deactivate it immediately and review CloudTrail for any use of it.
- Identify and fix the application path that placed the credential into the prompt, and add input/output filtering (such as a Bedrock guardrail with a sensitive-information policy) to prevent recurrence.