Over two thirds of popular search results on Google have hidden malware, according to a report into malware distribution by Barracuda Networks.

The company analysed popular trending topics over a two-month period, and found that Google turns up twice the amount of malware as Bing, Twitter and Yahoo combined when used to search for these topics.

"We realised that attackers take advantage of popular search terms to get in front of as many eyes as possible," said Paul Judge, chief research officer at Barracuda.

"We set the system crawlers to look at Google, Bing, Yahoo and Twitter and figure out the popular search terms. Then we searched for those pages and analysed them for malicious content."

The analysis reviewed more than 25,000 trending topics and nearly 5.5 million searches, and found that 69 per cent of Google results for popular trending topics contained hidden links by malware distributors. This compares to 18 per cent for Yahoo, 12 per cent for Bing and just one per cent for Twitter.

Names of celebrities were highly favoured by attackers, and an NFL player and three actresses featured in the top 10 of terms most used by malware distributors.

Barracuda also analysed over 25 million Twitter accounts, both legitimate and malicious, to identify behaviour that could be regarded as suspicious.

The research suggests that only 28.87 per cent of Twitter users are "true Twitter users", defined by Barracuda as following and being followed by 10 users.

The company also found that 30 per cent of Twitter accounts have not posted a single tweet, and that 1.67 per cent of all Twitter accounts were suspended for malicious activity in the first half of 2010.

A Google spokesperson said in response to Barracuda's research that the firm works hard to preserve the quality of its index.

"We actively identify sites that serve malware or abuse our quality g uidelines in other ways," the spokesperson said.

"Sites that exploit browser security holes to install software (such as malware, spyware, viruses, adware, and Trojan horses) are in violation of our quality guidelines, and may be removed from Google's index."