The Bugbear e-mail virus is still going strong and could have infected hundreds of thousands of computers worldwide.

Estimates of the damage the virus has done are difficult to make. One anti-virus firm MessageLabs has reported 60,000 copies so far.

Bugbear was spotted on 29 September and the first copy of the worm was seen in Malaysia.

The UK, Australia and the US have been worst affected but the virus has emerged in 100 different countries.

Possessed printer

The mass-mailing computer virus is difficult to spot, coming in the form of a random e-mail and can also disguise itself when it replicates.

Bugbear facts

Infects only Windows PCs Exploits vulnerability in Outlook to replicate itself Can disable firewalls and anti-virus software Can distribute e-mails from recipient's account Can compromise secure transactions or passwords

"It will infect your computer and then choose a different name from your address book to send itself on to your contacts," said Graham Cluley from anti-virus firm Sophos.

"This makes it difficult to know who has infected who."

Ironically a bug in the virus that makes it confuse printers with computers means that printers are likely to suddenly start churning out reams of paper, an obvious clue to office workers.

"If your printer seems possessed by some kind of phantom then you probably have the Bugbear virus," said Mr Cluley.

Generally though the virus is not hitting workplaces are much as home users who have not taken anti-virus protection he said.

One of the only other ways to spot the virus is in the size of the attachment which is always 50,688 bytes.

The Bugbear virus has a vicious payload. It can compromise secure transactions and passwords, make computers vulnerable to hackers, disable anti-virus software and distribute potentially confidential e-mails.

It is likely to knock Klez.H off the top spot for number of infections this month and, like Klez, will be around for months to come said Mr Cluley.