Sophos, a world leader in protecting businesses against viruses,
spyware and spam, has revealed the top ten viruses and hoaxes
causing problems for businesses around the world during the month
of November 2005.
The report, compiled from Sophos's global network of monitoring
stations, reveals that, despite being detected very late in the
month, the Sober-Z worm has stormed to the top of the charts, and
at its peak accounted for one in every 13 emails sent. The
proliferation of Sober-Z has caused Netsky-P, the worm written by
teenager Sven Jaschan, to fall to second position after
dominating the number one spot for the past four months.
The top ten viruses in November were as follows:
The new Sober-Z worm, which currently accounts for a massive
42.9% of all viruses reported to Sophos, sends itself as an email
attachment and attempts to turn off security software on the user's
computer. Once the attached file is run, the worm scans the user's
hard drive for email addresses, in its search for other computers
to infect. The author of this worm has been operating anonymously
for more than two years, and this latest threat is the cyber
criminal's most widespread virus yet.
"Since we saw the first Sober worm back in October 2003, its
author has tried to improve upon tried-and-tested tricks to dupe
computer users into launching infected attachments," said Carole Theriault, senior
security consultant at Sophos. "This latest worm purports to be a
warning from CIA and FBI agents, accusing recipients of visiting
illegal websites. Mocking the feds is a sure-fire way of goading
the authorities, and you can't help but wonder whether the author
is desperate to be caught."
Sober worms are frequently bilingual, configured to spread in
both English and German. As well as posing as communication from an
FBI or CIA agent, Sober-Z also references the German version of
'Who Wants to be a Millionaire' as well as US star Paris
This month's chart consists of only three virus families -
Netsky, Mytob and Zafi, indicating that virus writers are
continuing to create variants of established threats, which prove
most effective for financial gain.
"The Sober family may seem as hard to exterminate as a colony of
cockroaches, but they can be stopped from infesting a network if
users remain vigilant when facing unsolicited emails," continued
Theriault. "These worms have posed little threat to computers armed
with first-class anti-virus and anti-spam software, and run by
users who follow safe computing practices."
The Mytob family continues to spread far and wide and the
variants make up half of the top ten, demonstrating the family's
persistent and varied attacks. Aside from Sober-Z, this month's
chart is dominated by the Mytob, Netsky and Zafi virus families -
showing that cyber criminals are increasingly bringing out new
variants of established threats in order to maximise their
Sophos's research shows that 2.7%, or one in 38 emails is viral.
Sophos now identifies and protects against a total of 114,082
viruses, an increase of 1,940 on last month.
In order to minimise exposure to viruses, Sophos recommends that
companies deploy a policy at their email gateway which blocks
unwanted executable attachments from being sent into their
organisation from the outside world. Companies should also run up-
to-date anti-virus software, firewalls and install the latest
The top ten hoaxes reported to Sophos during November 2005 were
"We advise all companies to consider circulating a policy on
virus hoaxes to curb the spread of these annoying emails that can
cause mail overload and results in down time and loss of profits, "
said Theriault. "Although they do not cause serious network damage,
certain hoaxes, such as the HIV Needle email, are cruel tricks that
can be very upsetting for those users receiving them."
Sophos has made available a free, constantly updated information feed for intranets and
websites which means users can always find out about the latest
viruses and hoaxes.
Graphics of the above top ten virus chart are also available.