note_beacon · Cobalt Strike MCP Server MCP: Risk & Policy

WHAT IT DOES

What note_beacon does on Cobalt Strike MCP Server

AI agents use note_beacon 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 note_beacon needs a policy

The tool adds or updates notes associated with beacons in a Cobalt Strike red team operation. These are reversible write operations (notes can be modified or deleted). While the server overall manages offensive security operations, this specific tool only creates or modifies metadata/annotations rather than executing commands, deleting data, or moving money.

From the tool's definition Tool description states 'Add or update a note on a beacon', which are reversible create and modify operations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

note_beacon Rate-limited

note_beacon 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": {
    "note_beacon": {
      "limits": [
        {
          "counter": "note_beacon_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 note_beacon

What does the note_beacon tool do? +

Add or update a note on 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 note_beacon? +

Register the Cobalt Strike MCP Server MCP server in PolicyLayer and add a rule for note_beacon: 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 note_beacon? +

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

Can I rate-limit note_beacon? +

Yes. Add a rate_limit block to the note_beacon 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 note_beacon completely? +

Set action: deny in the PolicyLayer policy for note_beacon. 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 note_beacon? +

note_beacon 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.