proxycheck is a simple tool that will work on a reasonable *nix system and may be used 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. Every such machine should be either secured properly or turned off permanently, but that's not an option, since in most cases there is either no administrator of such machines exists at all, or he has no clue about what's on that machine, or it's irrelevant for him.
Binary packages can be installed with the high-level tool pkgin (which can be installed with pkg_add) or pkg_add(1) (installed by default). The NetBSD packages collection is also designed to permit easy installation from source.
The pkg_admin audit command locates any installed package which has been mentioned in security advisories as having vulnerabilities.
Please note the vulnerabilities database might not be fully accurate, and not every bug is exploitable with every configuration.
Problem reports, updates or suggestions for this package should be reported with send-pr.