Google has revamped its anti-malvertising site, which was launched in February this year, by adding new educational content for all internet users, to address the problem of malicious software being surreptitiously embedded into online adverts.

Some cybercriminals use advertising as a way to distribute trojans, keystroke loggers and other potentially dangerous software. In total, 45857 unique malicious, advertising, and potentially unwanted programs were detected on users' computers in March, according to Kaspersky Security Network.

This supplements the custom search engine that can perform quick background checks on advertisers. Although it is mainly designed for advertising networks to check companies so they can avoid malicious adverts, consumers can use it as well. We ran a check on an advertiser and the results returned were clean.

To get the best results Google recommends people run searches on queries such as the advertiser's name, company name, and any URLs and domains associated with an ad. It also warns that the system is not full proof.

"Search results should not be considered the last word on a prospective customer, but one potential source of helpful information," the company said.

Because of the increasing problem of rogue security software being advertised online Google said people should always research a security product's reputation before downloading it or exposing their system to its scanning functions. The National Cyber Security Alliance maintains a list of free security checks offered by computer security vendors.