http://www.theregister.co.uk/2007/08/07/storm_worm_spike/
By Dan Goodin in San Francisco
7th August 2007
Security researchers are reporting a sharp increase in the number of
machines infected by the Storm Worm, prompting speculation that its
authors, who so far have limited their activities to spam, intend to use
it for more destructive purposes, such as launching massive denial of
service attacks.
In June and July, internet security provider SecureWorks counted 1.7m
unique hosts carrying the Storm Worm, compared with just 2,817 from
January to May, according to Joe Stewart, a senior researcher with the
company. The number of attacks blocked by SecureWorks has similarly
skyrocketed, from 71,342 for the first five months of the year to 20.2m
since June.
Just about anyone with an email account is painfully familiar with
Storm, whose most recent spam messages bear subjects such as "You've
received a greeting e-card from a worshipper." Once recipients follow
the link and install the malicious code, they become part of the same
network as the original sender and either churn out the same e-card
messages or spam containing PDF files that tout penny stocks.
The spike in the number of infected machines is leading to speculation
that the people maintaining the Storm network are aspiring to greater
things.
"In most cases, a botnet of 1,000 or 10,000 is plenty to do what these
guys want to do, which is spam or DDoS somebody," Stewart told El Reg.
"We're wondering if perhaps the idea of having a virtually unstoppable
DDoS net might be driving this."
One possible plan may be to build a network that could be leased out to
hackers so they can launch a massive attack on a large company or entire
country. Stewart, who frequently monitors underground forums where cyber
criminals advertise their products and services, says little is known
about the people connected with Storm. He has yet to see individuals
identify themselves as being affiliated with the network.
The Storm Worm got its name after malware-laced mass emails that first
spread in January promised information about winter storms that ravaged
Northern Europe. Since then, the email topics have changed many times,
demonstrating a strong ability in its authors to trick recipients into
clicking through so they become infected.
Storm Worm combines this social-engineering savvy with a technical
prowess that relies on peer-to-peer technology for updates rather than a
centralized command and control channel on an internet relay chat
network. And therein lies the secret to Storm's resiliency.
"Instead of being connected to a single IRC server, it's connected by
p2p, so there's no head to cut off," said Allysa Myers, a virus research
engineer at McAfee. "It's been difficult to do anything on a larger
level to try to kill this thing off."
Storm infections can also be extremely hard to detect and remove because
they frequently alter executables that get loaded during startup, rather
than relying on traditional, and better understood, techniques of
modifying the startup registry. For example, recent variants of the
Storm Worm, which also goes by the name of W32/Newar, "parasitically
infect" tcpip.sys files.
"It's something that has been used by a number of different families
over the last six months or so, and Newar [authors] have seen this
tactic used by other virus writers and have started to incorporate it,"
Myers said. ®
Received on Thu Aug 9 02:06:59 2007