Authorities arrest 10 suspected botnet data thieves

International authorities, with some help from Facebook, have arrested 10 people accused of operating a network of infected computers that stole personal information from millions of victims.

The Justice Department said Tuesday night that the F.B.I. and international agencies were helped in their investigations by Facebook, whose users were among those targeted by the malware, or malicious software, over the last several years. The agencies arrested people from Bosnia and Herzegovina, Britain, Croatia, Macedonia, New Zealand, Peru and the United States, the F.B.I. said.

The suspects used a chain of infected computers to form what was known as the Butterfly botnet, which spread a piece of malicious software called Yahos, officials said. Versions of the software have long been trafficked among criminals who spread it over social networks and by other means, compromising the security of infected PCs and letting criminals steal personal data, including credit card numbers.