Legitimate websites infected with malware outnumber infected adult sites by a ratio of 99 to one, according to a report from security software maker Avast.
Of all the sites found to be hosting spyware, Trojans, keyloggers and the like, Avast found that just one per cent were adult sites.
In the UK, for example, the free anti-virus software maker found more infected domains containing the word "London" than including the word "sex", and said it was clear that the number of infected adult sites was also declining.
This undermines arguments that avoiding adults sites drastically reduced the chances of malware infection.
"We are not recommending people start searching for erotic content but the statistics are clear for every infected adult domain we identify there are 99 others with perfectly legitimate content that are also infected," Avast's chief technology officer (CTO) Ondrej Vlcek said.
Nor are surfers safer sticking with tried-and-trusted sites. One infected domain Avast found was the smartphones section of the Vodafone UK website.
The mobile provider was found to be harbouring a malicious JavaScript redirect script that attempted to infect users' machines through an as-yet unpatched Windows Help and Support Centre hole, identified two weeks ago and given the tag CVE-2010-1885.
This type of infection accounts for 20 per cent of all infected UK pages, Avast revealed, with Vlcek revealing that this particular bug had been so effective because it "targets the most widely used version of Windows, and at the present time it is still unpatched. This means that even if a user is running a fully updated Windows XP SP3 with all the security patches, the user is still vulnerable".
Avast's results were produced from anonymous log reports submitted by users of its free security software since mid-2009. The reports include the malware type and the infected site it came from.
