These days, junk e-mail is more than annoying, it's often malicious. But there are ways to protect yourself from the dangers of spyware.

Spam is changing, and not for the better. Increasingly, spam is being used for really bad purposes. The Federal Trade Commission says it's one of the main ways hackers get malicious code onto people's computers.

Spyware can result in identity theft or allow a cyber crook to hijack your computer.

And here's the really scary part: in most cases when your computer is compromised, you'll never know it until something bad happens.

In the computer world, they're called "bots," which is short for "robots." Bots are computers that are infected with malicious software that let hackers -- bad guys anywhere in the world -- have full access to your computer via the Internet.

"And they use these bots in connected networks to send out spam. You've probably noticed spam (is) on the rise," said Marina Merritt, a computer security expert. "Or (bots are used) to attack other computers or other networks, or even to steal your personal information right off you computer."

That's right, you could be turned into a spammer, sending out those Nigerian e-mails, stock offers or even offers to buy cheap pharmaceuticals and not even know it.

And, of course, everything that's in your computer is at risk. Once hackers have infected your computer, they can see everything on your hard drive, including files and pictures.

They can even turn on your computer camera and spy on you. And using a keystroke logger, they can see everything you type.

Serry Winkler had spyware loaded on her computer. She found out it was infected when the cops showed up at her door.

"They explained that they had a warrant for my computer. And they came in and they explained that somebody had stolen a credit card online, bought some merchandise for Sears using the stolen credit card and used my IP address to do all this," she said.

"It was pretty obvious that if they had gone that far, they probably knew everything about my finances," she added.

So how do you protect yourself? Have good security software and keep it updated. Make sure you have the latest patches for your computer and don't open attachments or any e-mail from senders you don't know.