TechCrunch has restored access to comments on its European website but advised visitors to scan their computers following the Zeus infection earlier this week.

Following the website interception on Tuesday of this week, where an iFrame was infected with a Zeus Trojan-installer PDF file and the website was effectively offline for most of the day as browsers detected it as being malicious, the site said it is ‘tracking down the malware issue which arose'.

TechCrunch said: “The issue is now fixed, but if a browser like Chrome still tells you there's malware here, it's because we're also waiting for Google to re-crawl our pages and give us the all clear. If you are at all concerned, feel free to check your computer with an up-to-date anti-virus solution of which there are many on the market.”

Graham Cluley, senior technology consultant at Sophos, who identified the issue at the time, said: “Of course, it would have been nice if TechCrunch had posted a warning on its site as soon as the problem was identified - but this is better than nothing! If you visited TechCrunch Europe's website at the beginning of this week you would be sensible to scan your computer now - just in case.”

Mickey Boodaei, chief executive of Trusteer, said that the TechCrunch fiasco is all part of the rising problem of Zeus infections. He said: “Trusteer warned a while ago that the newer version of Zeus is very effective in avoiding detection by IT security software and the increased Zeus infection rates demonstrates this.

"We estimate that fraud losses due to Zeus specifically are going to triple in 2011 due to the increase in distribution and lack of coverage by anti-virus vendors. This latest infection of the TechCrunch web portal is just the tip of the iceberg.”