Rogue security software is now among the top threats to computer users around the world with the number of machines infected with such programmes increasing significantly, Microsoft said in a report released on Wednesday.
Rogue security software, also known as "scare ware," takes advantage of users' desire to keep their computers protected and lures them into paying for bogus program which is actually malicious codes often designed to steal personal information.
Microsoft's latest Security Intelligence Report showed that in the second half of 2008, Win32/Renos, a threat that is used to deliver rogue security software, was detected on 4.4 million computers, a rise of 66.6 percent over the first half of the year.
According to the report, two other families of rogue security software were detected on more than 1.5 million computers, putting them among the top 10 threats in the second half of 2008.
The Security Intelligence Report, using data gathered from hundreds of millions of computers worldwide, is released twice a year.
Based on the new findings, the report recommended that users should take proactive steps to protect themselves, such as using anti-malware products from known, trusted sources and keep them updated.
Users should also be cautious not to follow advertisements for unknown software that appears to provide protection, the report said.