From recent article at MIT Technology Review:
How ISPs Could Combat Botnets
Focusing on the top 50 infected networks could eliminate half of all
compromised machines.
Convincing Internet service providers to pinpoint infected computers on their networks could eliminate the lion's share of
zombie computers responsible for churning out spam and initiating other online threats, according to a new analysis.
The researchers analyzed more than 63 billion unsolicited e-mail messages sent over a four-year period and found more than
138 million unique internet addresses linked to sending out the spam. Typically such machines have been hijacked by
hackers and are corralled into a vast network of remote-controlled system known as a "botnet."
By correlating the Internet protocol addresses of these spam-sending machines with the networks maintained by Internet
service providers, the researchers found that about two-thirds of them were located in the networks managed by the 200
largest ISPs from 40 countries. The top-50 networks responsible accounted for more than half of all compromised IP
addresses. If these ISPs were to shut down, or block, the malicious machines on their networks, it could cut worldwide
spam by half.
"Those 50 ISPs are not the [dubious] ones we hear about," says Michel van Eeten, professor of public administration at the
Delft University of Technology in the Netherlands and one of the authors of a paper on the research, which will be
presented next month at the Workshop on the Economics of Information Security at Harvard University. "They are the ones we
deal with every day, and so are more approachable and are in the reach of government."
Rest here:
http://www.technologyreview.com/computing/25245/
