When Agents Look Like Beacons: NIDS Evasion by Model Context Protocol Traffic
Research shows Model Context Protocol agent traffic structurally resembles C2 beaconing and evades Suricata signatures and RITA behavioral scoring in testbeds.
An arXiv study demonstrates that Model Context Protocol (MCP) JSON-RPC traffic over Streamable HTTP mimics the polling patterns of C2 frameworks like Cobalt Strike and is not flagged as anomalous by standard enterprise defenses. In a Docker testbed with eleven traffic profiles across three TLS conditions, Suricata with the Emerging Threats Open ruleset produced near-zero alerts and RITA assigned a consistent 0.0 beacon score, regardless of jitter or TLS inspection. The authors propose an agent-native network indication standard using Agent-Native ALPN and out-of-band headers.
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