yara_scan_files · Velociraptor MCP Server MCP: Risk & Policy

WHAT IT DOES

What yara_scan_files does on Velociraptor MCP Server

AI agents invoke yara_scan_files to trigger actions in Velociraptor 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.

WHY IT NEEDS A POLICY

Why yara_scan_files needs a policy

YARA scanning involves executing a scan engine against files on a host system, which triggers external operations on potentially sensitive files. Given the Velociraptor DFIR context (which includes memory scans, remediation actions, and artifact collection), a YARA file scan actively runs pattern-matching code against filesystem targets — this is an Execute-category action.

From the tool's definition Tool name 'yara_scan_files' on a Velociraptor DFIR server; description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

yara_scan_files Rate-limited

yara_scan_files 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "yara_scan_files": {
      "limits": [
        {
          "counter": "yara_scan_files_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Velociraptor MCP Server, so you can run agents against it safely.

FAQ

Questions about yara_scan_files

What does the yara_scan_files tool do? +

yara_scan_files. It is categorised as a Execute tool in the Velociraptor MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on yara_scan_files? +

Register the Velociraptor MCP Server MCP server in PolicyLayer and add a rule for yara_scan_files: 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 Velociraptor MCP Server. Nothing to install.

What risk level is yara_scan_files? +

yara_scan_files is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit yara_scan_files? +

Yes. Add a rate_limit block to the yara_scan_files 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.

How do I block yara_scan_files completely? +

Set action: deny in the PolicyLayer policy for yara_scan_files. 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.

What MCP server provides yara_scan_files? +

yara_scan_files is provided by the Velociraptor MCP Server MCP server (snoe-findley/mcp-velociraptor). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.