Virus infections and prevention is not only what Computer Security is about. Most of the ways hackers use your computer never involve a virus but many other tools. Being secure is more about developing safe computing habits than using software to keep yourself safe. Yes, you do need to use Malware (antivirus and anti-spyware) programs to help stay secure but you also need to know the warning signs and avoid the pitfalls. Many hacks/attacks just install remote control software that is preconfigured to connect to a specific person, and being normal software, Malware software will not catch these.
Most current threats want to use your computer for the hackers' needs. Their goal is to own control of your machine and sell that control to someone who can use it. Hackers are known to sell this access to spammers and underworld agents, so hacking is very profitable. Because of this they are constantly changing their methods and being crafty about hiding what is going on. They use Human Engineering, the art of fooling someone into clicking or giving out information, to get you to run their programs that take over your computer.
Most of these hackings have only one fix when they happen to your computer and that is to format your computer and reinstall the software from scratch, applying all patches and current threat management (anti-virus) programs. Because the fix has to be so drastic you must do your best not to get hacked.
So what can you do? The main thing is always question anything that is sent to you in Email or by IM that is a link or a program. Never click on links until you have verified them. If the email came from a bank or credit card company, call the company first. If an offer in email sounds too good to be true, like free money for doing something or a free item, it is too good. If the contact was from a friend or coworker, check with them by email, IM or phone. Having a live acknowledgement is the best. It is never bad to ask questions of the person who sent the message, or a computer support person, about something you received if in doubt.
K-State blocks hacked computers from accessing the network and Internet so computer security is not something that can be ignored. Be a smart computer user, don't be afraid to ask questions.