# server_file_write

Write file to C2 server (auto-creates parent dirs)

Agent View of the PolicyLayer registry record for `server_file_write`. HTML page: https://policylayer.com/tools/0xyg3n-claude-c2/server-file-write

## Facts

- Tool: `server_file_write`
- Server: Claude C2 (`0xyg3n/claude-c2`) — https://policylayer.com/tools/0xyg3n-claude-c2.md
- Homepage: https://github.com/0xyg3n/claude-c2
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "server_file_write",
    "arguments": {}
  }
}
```

## Why server_file_write is rated Medium

This tool creates or modifies files on a C2 (command and control) server, which is a reversible write operation. Severity is high because writing arbitrary files to a C2 infrastructure server could enable persistence, privilege escalation, or lateral movement if an AI agent is compromised or misused.

From the tool's own definition: "Tool name is 'server_file_write' and description states 'Write file to C2 server (auto-creates parent dirs)' — explicitly performs file creation/modification."

## Use case

AI agents use server_file_write to create or update resources in Claude C2, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Claude C2 environment.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Claude C2:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "server_file_write": {
      "limits": [
        {
          "counter": "server_file_write_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Claude C2 (93)

- `kill` — Destructive — https://policylayer.com/tools/0xyg3n-claude-c2/kill.md
- `mv` — Destructive — https://policylayer.com/tools/0xyg3n-claude-c2/mv.md
- `persist_remove` — Destructive — https://policylayer.com/tools/0xyg3n-claude-c2/persist-remove.md
- `reg_delete` — Destructive — https://policylayer.com/tools/0xyg3n-claude-c2/reg-delete.md
- `rm` — Destructive — https://policylayer.com/tools/0xyg3n-claude-c2/rm.md
- `timestomp` — Destructive — https://policylayer.com/tools/0xyg3n-claude-c2/timestomp.md
- `amsi_bypass` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/amsi-bypass.md
- `bypassuac` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/bypassuac.md
- `defender_exclude` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/defender-exclude.md
- `etw_patch` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/etw-patch.md
- `execute_assembly` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/execute-assembly.md
- `firewall_rule` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/firewall-rule.md
- `generate_payload` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/generate-payload.md
- `get_payload` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/get-payload.md
- `getsystem` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/getsystem.md
- `inject` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/inject.md
- `keylog_start` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/keylog-start.md
- `keylog_stop` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/keylog-stop.md
- `mcp_add_tool` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/mcp-add-tool.md
- `mcp_append_code` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/mcp-append-code.md
- `mcp_restart` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/mcp-restart.md
- `mimikatz` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/mimikatz.md
- `persist_registry` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/persist-registry.md
- `persist_schtask` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/persist-schtask.md
- `persist_service` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/persist-service.md
- `persist_startup` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/persist-startup.md
- `persist_wmi` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/persist-wmi.md
- `portscan` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/portscan.md
- `powershell` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/powershell.md
- `privesc_check` — Execute — https://policylayer.com/tools/0xyg3n-claude-c2/privesc-check.md
- …and 63 more: https://policylayer.com/tools/0xyg3n-claude-c2.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=0xyg3n-claude-c2 · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/0xyg3n-claude-c2