A report [PDF] by Google researchers has warned of a huge rise in fake antivirus software that tricks users into paying for a useless software suite.
According to the team fake antivirus software now accounts for 15 percent of all online malware and is responsible for 50 percent of all malware delivered by advertising, a fivefold increase in a single year.
“Fake AV attacks spread easily without requiring any vulnerability on a victim’s computer system,” said the team.
“Additionally, Fake AV distributors attempt to maximise their reach by posting Ads that lead to the Fake AV distribution sites, or funnelling traffic through search engine optimised web sites that are designed to rank highly for popular keywords.”
Using data from 2009 the team saw fake antivirus software rising from 3 per cent of infected domains to 15 per cent.
In January 2009 there were 93 domains host fake antivirus software but by the end of the year this had risen to 587.
The team also reported that legitimate security software was having increasing problems identifying the fake antivirus code, and so Google has developed software to speed up detection.
Fake antivirus adverts are not uncommon online but have been growing steadily as they can be both highly profitable and easy to set up. In addition they can function on fully patched PCs since they exploit no software vulnerabilities.