Are you a "Botnet"

The illicit trade in compromised PCs
By John Leyden
Published Friday 30th April 2004 14:43 GMT

Information Security 2004 Investigators are piecing together the
complex relationships between the virus writers, middlemen and
criminal gangs held largely responsible for the growth of spam in
recent months.

Viruses such as My-Doom and Bagle surrender the control of infected
machines to hackers. This expanding network of infected, zombie
machines can be used either for spam distribution or as platforms for
DDoS attacks, such as those that many online bookies have suffered in
recent months. By using compromised machines - instead of open mail
relays or unscrupulous hosts - spammers can bypass IP address
blacklists.

The IP addresses of compromised machines are traded over IRC networks
by either the virus authors themselves or middlemen with payments
directed towards anonymous online accounts or (less frequently) via
Western Union money transfers. In February German magazine c't
reported how it was able to buy access to infected machines - commonly
described in the parlance of spammers as "BotNets" - from virus
writers. The value of the BotNet market remains unclear but the
problem is growing and police investigations, assisted by anti-spam
activists, into the illegal trade are taking place on both sides of
the Atlantic.

Detective Chief Superintendent Les Hynds, head of the UK's National
Hi-Tech Crime Unit, told El Reg: "The trade of BotNets on compromised
machines is becoming an industry in itself. Organised crime is making
use of this industry."

In a conference call that accompanied the announcement of a legal
crusade by the US's biggest ISPs against large scale spammers last
month, legal officers described a network of middlemen, hackers, 'cut
out' companies and criminals (often based in Eastern Europe) that made
anti-spam investigations more difficult. The resale of compromised
machines is growing more sophisticated with dealers culling lists to
offer access to high-bandwidth machines at a premium or even offering
trial purchases as sales promotions. Anti-spam organisations are
indirectly noticing the effects of this change in sales tactics.

Mark Sunner, chief technology officer at email security firm
MessageLabs, said much of the spam it blocks comes from IP ranges
allocated to high-speed cable modem or ADSL accounts, such as
roadrunner and MSN in the US. MessageLabs reckons two thirds of the
spam it blocks originates from computers infected by viruses such as
Sobig-F or Bagle. Spam volumes are growing. More than two thirds of
the email passing through MessageLabs systems so far this month was
spam compared to 53 per cent for March as a whole. ®
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