2012, NEW DELHI: Cyber criminals may have attempted to siphon off anywhere between 60 million euros and 2 billion euros in fraudulent transfers from at least 60 banks globally, a McAfee and Guardian Analytics study today said.

The study highlighted a highly sophisticated, multi- tiered, global financial fraud ring that is comprised of at least a dozen groups use active and passive automated transfer systems to steal high value amounts from high balance accounts.

"This fraud empire, dubbed Operation High Roller, has impacted every class of financial institution: credit union, large global bank and regional bank, using smaller and less detectable automated transactions," McAfee said in a statement.