Federal prosecutors have charged two men with using a computer botnet to launch crippling Web attacks on Amazon, eBay, and Priceline, and then bragging about them in online hacker forums.

Dmitry Olegovich Zubakha, 25, of Moscow, was arrested in Cyprus this week for his role in attacks taking place in June and July of 2008. One of those lasted three days and prevented Amazon customers from completing online transactions, according to an indictment unsealed Thursday. In the weeks that followed, Zubakha—who went by handles Eraflame, Dima-k17, and DDService—periodically visited hacker forums to take responsibility for the DOS (or denial-of-service) attacks and to post stolen credit card numbers he had obtained, prosecutors further alleged. In the same forums, he marketed hacking services including for-rent botnets.

Sergey Viktorovich Logashov was a co-conspirator in the DOS campaign, which also hit eBay and Priceline. This is all according to the 12-page indictment filed in US District Court in Seattle. At one point, he allegedly called Priceline and advertised his expertise in stopping the attacks, which were causing the websites to become unresponsive by bombarding them with more traffic than they could handle. Using a fleet of compromised computers, they overwhelmed their targets by causing huge numbers of requests for "large and resource intensive webpages on a magnitude of 600 percent to 1000 percent of normal traffic levels," prosecutors wrote in the indictment.

Zubakha and Logashov, which Seattle US Attorney John Durkan referred to as "cyber bandits," were each charged with conspiracy to intentionally cause damage without authorization to a protected computer and intentionally causing damage to a protected computer resulting in a loss of more than $5,000. Zubakha was also charged with aggravated identity theft and possession of stolen data for more than 28,000 credit cards. They have yet to appear in court to answer the charges.