The Federal Security Service (FSB) and Ministry of the Interior (MVD) arrested two brothers, who are believed to be the ringleaders of the operation, and six other accomplices.

The gang secreted the malware in the bookmarks of popular Web sites, stealing data from Web users during frequent drive-by downloads.They used a network of mules to divert funds to other accounts for withdrawal from cash machines.

Russian authorities say the gang looted at least £1.3 million from 90 accounts during a six-month spree, but may also have been responsible for a worldwide carberp exploit that has netted as much as £2.8 million in a recent three-month period in Russia alone.