Lscan3 is a re-write of Mixters’ lscan02.c to include ssh, smtp, http, https, snmp and a few other small additions.
You can download it from the following link: https://packetstormsecurity.com/files/download/25843/lscan3.c
Source: https://packetstormsecurity.com/files/25843/lscan3.c.html