Exitmap is a fast and modular Python-based scanner for Tor exit relays. Exitmap modules implement tasks that are run over (a subset of) all exit relays. If you have a background in functional programming, think of exitmap as a map() interface for Tor exit relays. Modules can perform any TCP-based networking task; fetching a web page, uploading a file, connecting to an SSH server, or joining an IRC channel.

In practice, exitmap is useful to monitor the reliability and trustworthiness of exit relays. Mainly, we use exitmap to check for false negatives on the Tor Project’s check service and to find malicious exit relays . It is easy to develop new modules for exitmap; just have a look at the file HACKING in the doc/ directory, or check out one of the existing modules.