This is the latest in a series of monthly charts counting down
the ten most frequently occurring viruses as compiled by Sophos, a
world leader in corporate anti-virus protection.
For April 2001, the chart is as follows, with the most
frequently occurring virus at number one:
"April's top ten is dominated by the Magistr worm," said Graham
Cluley, senior technology consultant at Sophos Anti-Virus.
"This virus is particularly notable because it contains its own
SMTP client and so doesn't rely on using Outlook or other email
programs to spread. However, it does rely on users opening it once
it arrives so the message to users is simple - don't open
April also saw the payload date of the Chernobyl (CIH) virus. Every
year on April 26th (the anniversary of the Chernobyl incident) the
virus attempts to overwrite infected systems' hard disks and wipe
their BIOS chips, effectively leaving computers unusable. The virus
was first seen in June 1998 and caused significant amounts of
damage to computers in April 1999 and April 2000. This year saw
fewer reports of the virus than in previous years - even so,
clearly many people have failed to keep their anti-virus protection
sufficiently up to date.
1288 new viruses were discovered and protected against by Sophos
during April 2001.
The total number of viruses Sophos detects and protects against
Compiled by Sophos's technical support team, the top ten chart
is collated from calls to Sophos's 24 hour, 365 days a year
technical support line.
Graphics of the above Top Ten chart are available here.