Sophos, a world leader in protecting businesses against viruses,
spyware and spam, has revealed the most prevalent malware threats
and hoaxes causing problems for businesses around the world during
The report, compiled from Sophos's global network of monitoring
stations, reveals that the Netsky-P worm, first seen in March 2004,
remains the most widespread piece of malware spreading via email.
The family of Mytob worms are also causing multiple infections,
with five variants appearing in the top ten.
Sophos identified 1,538 new threats in May, bringing the total
of malware protected against to 122,634. The majority of the new
threats (85.1%) were Trojan horses, while just 12.3% were worms or
The proportion of email which is virus infected has dropped
considerably over the last year as hackers have turned from
mass-mailing attacks to targeted Trojan horses. In May 2005, one in
every 38 emails was infected, now this number is just one in
The top ten list of malware in May 2006 reads as follows:
"Netsky-P's strong position at the top of the chart shouldn't
fool anyone into thinking that the malware problem is in the past.
The threat environment is actually becoming much more sinister, as
we see more targeted malware attacks use spyware technology to
snoop upon individuals and businesses," said Carole Theriault, senior
security consultant at Sophos. "Businesses need to think more
holistically about their IT defences. Anti-virus protection at both
the gateway and the desktop must be accompanied by firewalls,
regular security patch upgrades and safe computing best practice."
The top ten hoaxes and chain letters in May 2006 were as
"This month's number one, the Olympic Torch hoax, warns
recipients that their hard disk will be 'burned' if a certain
attachment is opened," said Theriault. "Meanwhile, the popular
MySpace online community is beginning to experience hoaxes of its
own as members spread bogus warnings to each other. Hoaxes and
chain letters like these cause users to panic, and it's wise to
remember to always think twice and check the facts before
forwarding an email warning."
Graphics of the above top ten virus chart are available.