Bank-hacking code writer held, FBI says

WASHINGTON — International authorities have arrested a computer hacker believed responsible for creating the malicious computer code that infected as many as 12 million computers, invading major banks and corporations around the world, FBI officials said Tuesday.

A 23-year-old Slovenian known as Iserdo was snagged in Maribor, Slovenia, after a lengthy investigation by Slovenian Criminal Police there along with FBI and Spanish authorities.

His arrest comes about five months after Spanish police broke up the massive cyber scam, arresting three of the alleged ringleaders who operated the so-called Mariposa botnet, stealing credit cards and online banking credentials. The botnet — a network of infected computers — appeared in December 2008 and infected more than half of the Fortune 1,000 companies and at least 40 major banks.

Botnets are networks of infected PCs that have been hijacked from their owners, often without their knowledge, and put into the control of criminals.

Jeffrey Troy, the FBI's deputy assistant director for the cyber division, said Tuesday that Iserdo's arrest is a major break in the investigation. He said it will take the alleged cyber mastermind off the street and prevent him from updating the malicious software code or somehow regaining control of computers that are still infected.

Officials declined to release Iserdo's real name and the exact charges filed against him, but said the arrest took place about 10 days ago and the man has been released on bond.

"To use an analogy here," said Troy, "as opposed to arresting the guy who broke into your home, we've arrested the guy that gave him the crowbar, the map and the best houses in the neighborhood. And that is a huge break in the investigation of cyber crimes."

Troy said more arrests are expected.