According to anti-spyware company Webroot on Tuesday, spyware program CoolWebSearch self-installs malicious HTML applications and exploits security flaws in IE.
"This has vexed all of us," said Nick Lewis, managing director of Webroot. "For consumers, CoolWebSearch is probably on of the most vicious programs in terms of how nasty it is. It completely hijacks the browser so you can't do anything."
Webroot said that CoolWebSearch is the most dangerous program in its latest list of the 10 worst spyware and adware threats. The company's threat research team has also discovered new versions of rogue diallers, keystroke loggers and pornographic Web page displayers.
"The people who write this stuff are gaining sophistication in their coding practices as they attempt to evade detection and removal," said Richard Stiennon, Webroot's vice-president of threat research. "These 10 are the most insidious programs in terms of prevalence and effect."
Webroot's list of top 10 threats includes PurityScan, a program that displays pop-up ads onto computers and claims it can delete pornographic images on the user's computer; Transponder (vx2), an Internet Explorer "browser helper object" that monitors Web browsing and sends relevant advertisements; KeenValue, an adware program that collects personal information and sends advertisements to users; and Perfect Keylogger, a monitoring tool that records Web sites visited, keystrokes and mouse clicks. It logs passwords, account numbers and other sensitive information.
Webroot recommends that users should install Microsoft security patches, avoid using freeware and disable downloads via ActiveX in Internet Explorer.
"It's Internet users' choice to keep or remove these programs based on the information available to them," said Stiennon. "We’re making sure they have that information so they are making knowledgeable decisions."