Many pages on the DALnet website ( offer information on protection against hackers. Basically, don't share your passwords, don't load scripts you don't understand, don't type something someone tells you to type and be very careful of the URL's that are spammed to
you on ANY Network. Clicking on most of those spammed urls will infect you and make you another of the annoying drone spammers
How to protect your puter:

A good channel on DALnet for help is #nohack and their website is a good resource

Good free online scanner that is more likely to catch IRC type nasties:

ParaBrat @#mIRCAide DALnet