look for a tool called "appletree". the original site is www.superkuh.com but i can't find it on that site, there are few broken links. last version i saw was 1.12. it is a perl program (with source, of course) that get an ip list (txt) and try all these ip 4 a dictionary password. if it find a password, u can specify some options that clean logs, install rootkits etc.
let me know if u find it!
good work and good searchin