Hentai Trojan publishes your porn history

Malware lurking on file-sharing site Winny publishes an infected user's browsing history on a public web site and demands a fee to take it down.

The trojan mostly targets those downloading Hentai, which is a form of Japanese cartoon porn usually featuring young girls having unpleasant things done to them by aliens. Website Yomiuri reports that 5,500 people have so far admitted to being infected.

The virus, known as Kenzero, launches an installer requiring the user to enter personal information including their full name, date of birth, password, email address, postal address, gender, annual income, company name and telephone number "along with a few other things for good measure," according to Rik Ferguson, a senior security advisor at Trend Micro.

"While all this is going on, the malware is also automatically collecting details about the victim’s computer including user account, domain and computer name, OS version information, clipboard content, file use history and Internet Explorer favourites. It also grabs a few screen shots just in case they don’t already have enough dirt," Ferguson writes.

All the information is then published on a web site and the victim receives an email demanding a credit card payment of 1500 yen (£10), which it says is to "settle your violation of copyright law".

The email comes from a shell company named Romancing Inc, which also operates the web site on which the filleted information is published. Both are registered to a non-existent chap named Shoen Overns.