According to court documents, Alexey Mineev set up several "drop accounts" that were then wired funds stolen from banking and brokerage accounts between July and December 2007. He pleaded guilty to one count of money laundering on Wednesday, according to Mike Ruocco, deputy to Judge Paul Gardephe of the U.S. District Court for the Southern District of New York, who is presiding in the case.

The criminals would infect PCs with malicious Trojan software that would steal account numbers and passwords whenever victims logged into their accounts online. Authorities say that another conspirator, Alexander Bobnev, would e-mail Mineev screenshots of the hacked accounts showing how much money was being transferred into Mineev's drop account, along with instructions such as "Withdraw the money ... tomorrow."

Mineev would then move the cash, sometimes as much as US$10,000, to Russia, using services such as Western Union.

Trojans are malicious programs that users install on their computers, believing them to be benign. Hackers disguise them as things such as video codecs, screensavers, and even security patches.

Account theft is a growing problem for banks and brokerage firms. They want to keep offering customers low-cost online banking services but are also sustaining losses from international criminals. Once the money has been moved offshore, it is virtually impossible to recover, security experts say.