The recent arrests of three men in The Netherlands who allegedly controlled a network of more than 100,000 compromised computers will not likely curtail the criminal economy surrounding so-called bot nets, security experts said this week. The arrests, announced last week by The Netherlands' National Prosecution Service, follow the August capture of two men - one from Turkey and the other from Morocco - suspected of creating and spreading the Zotob worm, a program that also compromised computers in order to create a bot net.
Security experts applauded the successful investigations but remained pragmatic about the impact the arrests will have on the increasing use of bot nets as a means to facilitate online crime.
"We hope that it will cut down the activity of some of the bot net herders, but I am not too hopeful," said Mikko Hyppönen, chief research officer for antivirus firm F-Secure. "If creating these networks is still profitable, then they will still do it, and probably just be more careful."
The arrests, announced last Friday, are the latest counterstrike against criminals who use bot nets to attack corporate networks, capture sensitive and financial information and send bulk email messages such as spam and phishing attacks. In August, the FBI and Microsoft helped authorities in Turkey and Morocco track down two men suspected of creating and spreading the Zotob worm--a program that consisted of bot software modified to exploit a flaw in Windows 2000. In May, the US Federal Trade Commission kicked off an initiative to reduce the number of botnets able to send out spam and phishing email messages.
The latest arrest in The Netherlands was the result of an investigation by that nation's National High Tech Crime Center, the National Prosecution Service, and Computer Emergency Response Team of the Dutch government as well as several Internet providers. The arrest should be somewhat heartening for the European Union as computer systems hosted in the EU comprise the largest block of compromised systems in the world, according to data collected in the first half of 2005 by Prolexic Technologies, which has built a business by helping its clients deal with the denial-of-service attacks leveled by the controllers of some botnets.
Such systems are used for a variety of criminal enterprises, said Barrett Lyon, chief technology officer for Prolexic.
"We saw the extortion racket take off first, but now it is a mixture," Lyon said. "You are seeing extortion; you are seeing competitive-advantage attacks; and you are seeing censoring attacks."
Some websites have had to deal with denial-of-service attacks by bot nets because attackers believed the site to hold a certain point of view, he said.
The three Dutch suspects allegedly used the 100,000 computers in the bot net to take down a US company's website with a denial-of-service attack in an attempt to extort money from the company, the National Prosecution Service said in its statement. In addition, the bot herders -the name used by security researchers to describe those who control botnets - likely captured the log-in credentials to victims' bank accounts.