spawn_powershell · Cobalt Strike MCP Server MCP

WHAT IT DOES

What spawn_powershell does on Cobalt Strike MCP Server

AI agents invoke spawn_powershell to trigger actions in Cobalt Strike 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 spawn_powershell needs a policy

This tool allows execution of arbitrary PowerShell commands on remote systems via Cobalt Strike beacons. PowerShell execution can enumerate systems, modify configurations, install malware, exfiltrate data, disable security controls, and pivot laterally. The blast radius is critical: an AI agent could inadvertently execute destructive or exfiltrating commands, disable endpoint protections, or launch further attacks.

From the tool's definition Tool description states 'Execute PowerShell command on a beacon' — directly executes arbitrary code on a compromised system. Cobalt Strike is a red team framework where beacons are implants on target machines.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

spawn_powershell Rate-limited

spawn_powershell 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": {
    "spawn_powershell": {
      "limits": [
        {
          "counter": "spawn_powershell_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 Cobalt Strike MCP Server, so you can run agents against it safely.

FAQ

Questions about spawn_powershell

What does the spawn_powershell tool do? +

Execute PowerShell command on a beacon. It is categorised as a Execute tool in the Cobalt Strike 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 spawn_powershell? +

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

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

Can I rate-limit spawn_powershell? +

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

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

spawn_powershell 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.