Virus top ten: SirCam storms in at number one

The SirCam worm regained its top spot as the world's number one virus last month.

The worm, which first hit our screens in July, randomly selects files from the victim's My Documents folder and forwards them to the user's contacts. It also has the ability to morph both its title and email header, making it difficult for users and some anti-virus software to track down.

According to figures from anti-virus vendors, SirCam accounted for between 40 and 45 per cent of all infections last month.

The worm was also as number one virus in August, but in September was forced into the shade by the Nimda outbreak. However, while the publicity surrounding Nimda effectively killed it, SirCam's failure to make a big splash when it first appeared, may have helped it be so destructive in the long-term.

SirCam is still able to proliferate despite the fact anti-virus software has protected against the worm for over four months.

Graham Cluley, senior technology consultant for Sophos Anti-Virus, said: "The SirCam worm just seems like it's never going to die. There must be loads of people out there who haven't updated their anti-virus software, it's really quite scary.

Nimda's is no longer prevalent, despite the arrival of variants in recent days. According to Kaspersky Labs, Nimda doesn't even make it into the top ten of viruses, coming in at 14th.

Below is the full list of October's widespread viruses, according to Kaspersky Labs:

1 I-Worm.Sircam 44.9 per cent
2 I-Worm.Hybris (family) 14.6 per cent
3 I-Worm.Anset 5.2 per cent
4 I-Worm.Magistr.a 3.8 per cent
5 I-Worm.HappyTime 3.5 per cent
6 Macro.Word97.Thus (family) 2.5 per cent
7 I-Worm.LoveLetter (family) 2.5 per cent
8 I-Worm.Magistr.b 2.4 per cent
9 Macro.Word97.Ethan 1.7 per cent
10 Backdoor.Death 1.1 per cent