Description:

Proxycheck is a simple tool to quickly check whenever a given host or set of
hosts has open proxy server running. Open proxies of various kinds are (ab)used
nowadays for various evil things like sending mass spam, hacking into your
machine, making denial of service attacks (DoS) and the like. To stop the abuse
of open proxy servers, one need to know whenever any machine runs such service
or not.
This command-line tool, proxycheck, may be used for such purpose. Currently, it
understands 3 types of proxy servers: HTTP proxies that allows you to CONNECT
to any host:port, SOCKS v4 and v5 proxies (www.socks.nec.com), and wingate
"telnet" proxy servers.