Spyware and the ad-serving software called adware are widely despised for their sneaky distribution tactics, unauthorized data gathering and slowing effect on PCs. As many as 80 percent of consumers' machines are infected with the annoying software, experts say.
Hacking is about money these days, not about digital graffiti. Organized crime is involved in commandeering the systems of unwitting owners and then using these in targeted attacks at companies. Zombies--as hijacked PCs are known--are used to send spam and extort businesses.
Phishing attacks have exploded over the past few years. The e-mails look like they come from legitimate companies, such as banks and e-commerce sites, but are used by criminals to try to trick Web users into revealing personal information and account details.
The level of spam has increased 65 percent in the past four years. Seventy percent of all e-mail today is junk. An entire antispam industry, lawmakers and Bill Gates are all fighting the pest--but so far, to no avail.
Identity theft has topped the list of fraud complaints at the Federal Trade Commission for several years. Most ID thieves target credit cards, followed by phone or utilities accounts, bank accounts and employer data.
Viruses and worms have plagued computer users for at least two decades and are the largest source of financial damage related to computer crime, according to the FBI. As of mid-January, 2006, there were more than 150,000 known viruses.