This is whois3, a very simple and generic whois client. This client, unlike the "classic" whois client, does not check for supported flags at the client side, except for -h (whois host) and -p (whois port). The syntax checks for flags are made at the server side. The default host and port of whois3 is whois.ripe.net at port 43 (or to be more exact, the tcp port specified for whois in /etc/services). Try whois3 help.
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.