Beware the 'sex virus'

A new fast spreading email worm is designed to obliterate all Word, Excel, Access and PowerPoint documents as well as Acrobat and Photoshop files on an infected computer.

And it's set to become active on Friday February 3, repeating the process on the third day of every subsequent month.

Dubbed the Kama Sutra worm — but also known as Nyxem.E, Blackworm, MyWife, and Grew.A — it appears in email inboxes with subject lines like "hot movie", "A Great Video" or "Crazy illegal Sex!", although subject lines and body text varies greatly.

If the attachment on the email is clicked, the virus launches, disabling any installed anti-virus software, and causing the infected computer to send similarly infected emails to every address on the hard drive.

It also tries to spread by seeking out machines on the same local network.

The mouse and keyboard may also be disabled.

But that's just the tip of the proverbial iceberg. The virus also installs the program due that, on the third day of every month, will delete all MS Office, Acrobat and Photoshop files — some of the most common used in day-to-day work.

Apart from targeting the computer's harddrive it's also programmed to hit external data-storage devices.

And according to experts at Verisign, the deletion program works.

The virus first appeared on January 16 but has already racked up numbers of between 300 000 and 500 000 infected machines.

It's possible to tell if you've been infected if you clicked on an email attachment and your mouse and keyboard froze, forcing you to reboot your PC.

To disinfect, reinstall an updated anti-virus program that protects against the worm and scan the system to make sure you haven’t been infected.

Even if you don’t suspect an infection, experts advise updating your anti-virus software definitions and running a full system scan to ensure you haven’t been caught out.

They also advise making regular backups of valuable files.

» The virus targets the following file types:
DMP (Oracle files)
DOC (Word document)
MDB (Microsoft Access)
MDE (Microsoft Access/Office)
PDF (Adobe Acrobat)
PPS (PowerPoint slideshow)
PPT (PowerPoint)
PSD (Photoshop)
RAR (Compressed archive)
XLS (Excel spreadsheet)
ZIP (Compressed file)