... An insidious new Internet attack that hijacks a victim's Internet connection and stealthily installs a barrage of adware and spyware is targeting businesses and organizations across the United States.

The two-pronged attack, which has been ongoing since early March, has afflicted an estimated 20,000 computers, according to Ken Dunham, director of malicious code at IDefense, a Virginia-based Internet security company.

It starts with an assault known as DNS poisoning: Domain name system servers, which guide Internet traffic, are fooled into directing anyone heading to any .com Web site--for example, www.cnn.com or www.americanexpress.com--to a malicious Web site that the attackers control. That Web site then surreptitiously installs a wide range of adware and spyware on the victim's computer....

Security researchers have discovered an attack aimed at would-be visitors to Google.com, one that attempts to download malicious programs onto the computers of people who simply mistype the search giant's Web address. According to security specialist F-Secure, unsuspecting Web surfers may be bombarded with various types of Trojan horse threats, spyware and backdoors when they go to "Googkle.com." The scheme is meant to take advantage of sloppy or hurried typists, given that on most keyboards the letter "k" key sits next to the "l" needed to type "Google."