beacon_upload_file · Cobalt Strike MCP Server MCP

WHAT IT DOES

What beacon_upload_file does on Cobalt Strike MCP Server

AI agents use beacon_upload_file to create or update resources in Cobalt Strike MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Cobalt Strike MCP Server environment.

WHY IT NEEDS A POLICY

Why beacon_upload_file needs a policy

This tool transfers a file to a compromised system under attacker control. While reversible, it enables placement of malware, scripts, or tools on the target and represents modification of the target's filesystem. Severity is high because successful execution could deliver payloads, backdoors, or lateral movement tools. Confidence is high because the function is explicit in both name and description.

From the tool's definition Tool name 'beacon_upload_file' and description 'Upload a file to a beacon' indicate the tool creates or modifies data on a remote system (a beacon, which is an implant/agent in Cobalt Strike).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

beacon_upload_file Rate-limited

beacon_upload_file stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "beacon_upload_file": {
      "limits": [
        {
          "counter": "beacon_upload_file_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about beacon_upload_file

What does the beacon_upload_file tool do? +

Upload a file to a beacon. It is categorised as a Write tool in the Cobalt Strike MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on beacon_upload_file? +

Register the Cobalt Strike MCP Server MCP server in PolicyLayer and add a rule for beacon_upload_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 Cobalt Strike MCP Server. Nothing to install.

What risk level is beacon_upload_file? +

beacon_upload_file is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit beacon_upload_file? +

Yes. Add a rate_limit block to the beacon_upload_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.

How do I block beacon_upload_file completely? +

Set action: deny in the PolicyLayer policy for beacon_upload_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.

What MCP server provides beacon_upload_file? +

beacon_upload_file is provided by the Cobalt Strike MCP Server MCP server (mickeydb/cobalt-strike-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.