Reads a file using the ReadFile win32 API call. Returns the contents of that file.
AI agents call read_file to retrieve information from Mythic MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Although this is a Read category tool, severity is high because it operates within a penetration testing framework (Mythic C2) where file contents could expose sensitive credentials, source code, encryption keys, or system configuration data.
From the tool's definition Tool name is 'read_file' and description states it 'Reads a file using the ReadFile win32 API call. Returns the contents of that file.' This is purely a read operation with no side effects.
Documented attack patterns abuse exactly the kind of access read_file gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mythic MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for read_file:
{
"version": "1",
"default": "deny",
"tools": {
"read_file": {}
}
}read_file is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Reads a file using the ReadFile win32 API call. Returns the contents of that file. It is categorised as a Read tool in the Mythic MCP MCP Server, which means it retrieves data without modifying state.
Register the Mythic MCP server in PolicyLayer and add a rule for read_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 Mythic MCP. Nothing to install.
read_file is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the read_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 read_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.
read_file is provided by the Mythic MCP server (xpn/mythic_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 6 Mythic MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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6 Mythic MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.