LONDON – A new computer worm dubbed "Netsky-D" (search) was clogging e-mail systems around the world after emerging on Monday, a security expert said.
The worm is particularly difficult to root out because it lands in e-mail boxes using a number of different subject lines such as "re:details" or "re:here is the document."
"It arrives with an attached pif file [program information file] and it's already extremely widespread," said Graham Cluley, senior technology consultant at Sophos Plc.
He said experts do not think the new virus is as big as MyDoom (search), which brought havoc to computer users and targeted Microsoft's Web Site, but that the full extent of Netsky-D's spread would be known as North America logs on.
When opened, the virus pif file will rapidly replicate itself, slowing down computers and e-mail bandwidth.
"We suspect people are more laid back about pif files because they may not have heard of them and may not realize they can contain dangerous code," Cluley said. "The best thing to do with this file is to delete it, don't open it."
Netsky-B, an earlier variant of the latest worm, was rated the third worst computer virus in February after MyDoom-A and Sober-C (search), according to Sophos, which writes anti-virus and anti-spam software.