"Network administrators now have a hacking tool that
can help them strike back at malicious attackers.
"LaBrea" is a free, open-source tool that deters worms and other
hack attacks by transforming unused network resources into
decoy-computers that appear and act just like normal machines on a
network. But when malicious hackers or mindless worms such as Nimda
or Code Red attempt to connect with a LaBrea-equipped system, they
get sucked into a virtual tarpit that grabs their computer's
connection -- and doesn't release it.
Worms trapped in the tarpit are unable to move along to infect
other computers. Stuck hackers first waste their time flailing away
at a non-existent machine; they are then forced to shut down their
hacking program or computer to escape."