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ATR-2026-00136criticalContext Exfiltrationexperimental

Tool Response Data Piggybacking

Detects malicious tool responses that embed sensitive data extraction within legitimate-looking results. The attack pattern embeds credential theft (SSH keys, API tokens, env vars) as a "by the way" addendum to a normal tool response, exploiting the agent's trust in tool outputs. Discovered via adversarial testing: 62/62 social engineering variants evaded prior rules.

Severity
critical
Category
Context Exfiltration
Scan Target
mcp
Author
ATR Threat Cloud Crystallization

Response Actions

block outputalertsnapshot

References

OWASP Agentic
ASI06 - Rogue ActionsASI08 - Data Leakage
OWASP LLM
LLM01:2025 - Prompt Injection
MITRE ATLAS
AML.T0054