Scan a file with YARA rules for malware detection. Uses bundled signature-base rules by default (Mimikatz, CobaltStrike, webshells, ransomware, etc.).
AI agents invoke yara_scan_file to trigger actions in Windows Forensics MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
This tool executes YARA scanning operations against files, which involves running a pattern-matching engine over file contents. While read-like in intent (detection/analysis), it actively executes a scanning process with external rule sets (signature-base: Mimikatz, CobaltStrike, webshells, ransomware).
From the tool's definition 'Scan a file with YARA rules for malware detection' — triggers execution of YARA rule engine against a file on the system
Documented attack patterns abuse exactly the kind of access yara_scan_file gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Windows Forensics MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for yara_scan_file:
{
"version": "1",
"default": "deny",
"tools": {
"yara_scan_file": {
"limits": [
{
"counter": "yara_scan_file_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}yara_scan_file stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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Scan a file with YARA rules for malware detection. Uses bundled signature-base rules by default (Mimikatz, CobaltStrike, webshells, ransomware, etc.). It is categorised as a Execute tool in the Windows Forensics MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Windows Forensics MCP Server MCP server in PolicyLayer and add a rule for yara_scan_file: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Windows Forensics MCP Server. Nothing to install.
yara_scan_file is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the yara_scan_file rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for yara_scan_file. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
yara_scan_file is provided by the Windows Forensics MCP Server MCP server (x746b/winforensics-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Windows Forensics MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
61 Windows Forensics MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.