That being said, antivirus software only works if the viruses are known. "They're reactive. The virus has to exist before you can do anything about it," says Jon Ramsey of SecureWorks. "We see there is so much malware out there that antivirus (software) has a very difficult time keeping up with it. It may be out there for several weeks before it's added to the list of known problems."
SecureWorks unearthed a particularly successful scam recently in which e-mails, disguised as messages from the Better Business Bureau, were sent to executives and business owners. The perpetrator of the scam got enough specific information on his targets to tailor missives with their name, title and place of work -- easily gathered from social networking sites.
"If you're the vice president of sales and you get something from the Better Business Bureau, you can bet you're going to click on it. And that particular scam is still going on."
By following the link in the e-mail, victims' computers were infected with a virus that recorded and sent everything they typed into a browser back to the hacker.
Getting antispyware software is important to thwart such attacks. Spyware, which is installed without a computer owner's knowledge, can do any number of things, from hijacking the Web browser to stealing personal information such as credit card numbers and bank account information.
Open attachments from strangersSecret crushes, long lost friends saying "what's up" or strangers hawking cheap drugs -- you'll never know unless you peek at that e-mail.
"We've seen a rash of people infecting video files, pictures, everything," says Jon Ramsey of SecureWorks. "Never click on an executable attachment. There's just no purpose. You have to go through a risk assessment and you have to gauge it."
Some of the fun things that can happen from opening an executable file include infecting your computer with a Trojan horse or virus, which can easily lead to identity theft.
"Whether it's a link to a Web site where something is downloaded or an actual download from the attachment, the first thing that will happen is that they try to take over control of the computer," says Ramsey.
"Then they hide themselves, so if you were to look for the file or applications running, you wouldn't see it. Then they take all of the information on the computer, for instance, in Windows protected storage, and they send it back to the hacker. Whether you type to someone, go to a bank account, click on a button -- all of this can be taken back to the hacker and they can look at everything that you type."
Social networking sites, such as MySpace.com and LinkedIn.com, present special risks. These playgrounds of the computing hoi polloi are generally eschewed by savvier users due to the insecurity of user-made pages.
For instance, "Myspace doesn't actually create its content; it's created by the Internet, so it's possible that someone could make a page that is populated by malicious stuff that people could browse to," says Ramsey.
Stuff your wallet with juicy identifying tidbitsWallets and purses are more than just handy cash-carrying devices. They often have credit cards, identification, insurance information and even Social Security cards. Obviously, more is better if you'd like to become the prey of fraudsters. Losing or misplacing a wallet or purse can cause more problems than just the hassle of replacing all those cards and buying a new bag.
Armed with your date of birth, Social Security number and mailing address, there's no limit to the damage thieves could cause.
Surprisingly though, it's not always a masked stranger behind identity fraud. The perpetrators are often someone the victim knows.
"Most commonly, someone you know uses your bank account or your credit card without your consent," says Fred Cate, director of the Center for Applied Cybersecurity Research. "So that could be someone like a family member, which is very, very common -- a teenage son or daughter or maybe a stepparent who's living with you."
You might say, "But my family and friends aren't criminals! We're all upstanding pillars of the community." Actually, you can never be too sure.