Conficker is now caught out using a tried & testsed standard GNU/Linux tool: nmap

Please refer to this page for details, but the summary basically goes like this:

nmap -PN -T4 -p139,445 -n -v --script=smb-check-vulns --script-args safe=1 [targetnetworks]

note: you'll need to download the beta "4.85BETA5" & compile from source

now you can pick up infected (win) systems on your network

happy hunting ;)