The market for anti-spyware tools will hit $305 million by 2008, according to new research from IDC. The firm also revealed that it estimates 67 percent of consumer PCs are infected with some form of spyware.

In 2003, IDC reported the market for anti-spyware tools to be only $12 million. That number is forecast to grow by 260 percent in 2004.

IDC cites the ease with which spyware infiltrates user PCs among the reasons for the growth of spyware and the tools that fight it. Spyware, also known as adware or malware, is often bundled with downloadable applications and it can also "infect" PCs just by simply browsing.

"Today, more malicious spyware can easily infiltrate corporate firewalls," said Brian Burke, research manager of Security Products at IDC, in a statement. "These programs make their way into the corporate intranet under the guise of less-threatening network traffic and, once in, they can wreak havoc."

Spyware is not always malicious. Some of the most common occurrences of spyware are of the adware nature that are planted by advertisers to track when users see an ad or visit a site and when they return.

Malicious uses of spyware include browser hijacks that redirect users and forms that allow for key logging, PC scanning and data corruption. IDC warns that at its worst spyware can lead to theft of company trade secrets and identity theft.

"The range of spyware from semi-legitimate to completely criminal is a challenge to consumers and corporate customers," Chris Christiansen, program vice president of IDC's Security Products and Services programs, said in a statement.

IDC said that anti-spyware features are soon to become key components of server-based gateways, security suites and anti-virus products.

The scourge that is spyware was identified in a recent IDC survey as the fourth greatest threat to enterprise security. Other surveys have also shown similar or greater infestations of spyware. A recent AOL/National Cyber Security Alliance (NCSA) Online Safety Study, found that 80 percent of scanned computers actually had some form of spyware or adware present.

The U.S. government hasn't been idle in the fight against spyware, either. In October Congress passed a slew of anti-spyware laws designed to deter and penalize spyware offenders.