The gang, said to be Russian-speaking, has hit a number of financial institutions although the exact number is unknown, reports, which cited a Russian computer-security firm called Kapersky Lab ZAO, said. That firm’s website made no mention of the issue that this publication was able to identify; this publication is contacting Kapersky Lab ZAO for comment.

If confirmed, the report highlights how cybercrime has become a major headache for banks, including those catering to the wealthy, where privacy around financial information is understandably a concern. (To view a feature article exploring the issues, see here.) Last year, JP Morgan confirmed that millions of account details had been affected by hackers although no evidence was found of actual thefts.

"Cybercriminals have got the infection-to-cash cycle down to a fine art, proving crime does pay when the victim's perimeter can be bypassed and systems manipulated at will,” Mark Bower, vice president, product management at Voltage Security, a tech firm, said in a note about the latest revelations.

“Today, there are few defences against this level of attack sophistication - but new methods have emerged to fight back, especially data-centric security which works by making stolen data completely useless to the criminal who steal that are `unnatural’ or `rare’ in normal operations such as `tricking’ the balance of accounts. Clearly it is impossible to scrutinise each and every such operation. Thus a technology that looks at the aggregate effect of such operation over time is something required in today’s landscape,” Shulman said.