Monitor for new TGTs without harvesting/renewal. Watches for new TGT events and displays them as they occur. Lighter weight than harvest - just observation.
AI agents call rubeus_monitor to retrieve information from Rubeus MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Although the tool is part of a Kerberos abuse toolkit and can reveal sensitive ticket information that an attacker could leverage, the tool itself performs only passive observation (Read). It retrieves and displays TGT event data without executing commands, modifying tickets, or triggering destructive operations.
From the tool's definition Tool description states 'Monitor for new TGTs' and 'just observation' — it watches and displays Kerberos ticket events without modifying, renewing, or harvesting them. No side effects on the monitored data.
Attacks that exploit this kind of access
Monitor for new TGTs without harvesting/renewal. Watches for new TGT events and displays them as they occur. Lighter weight than harvest - just observation. It is categorised as a Read tool in the Rubeus MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Rubeus MCP Server MCP server in PolicyLayer and add a rule for rubeus_monitor: 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 Rubeus MCP Server. Nothing to install.
rubeus_monitor 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 rubeus_monitor 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 rubeus_monitor. 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.
rubeus_monitor is provided by the Rubeus MCP Server MCP server (schwarztim/sec-rubeus-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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