A criminal gang with members in Russia, Ukraine and China has conducted a major cyber robbery on up to 100 banks, e-payment systems and other financial institutions worldwide, stealing over $1 billion ((£648, €878m).

An investigation involving Interpol, Europol, and computer security firm Kaspersky Labs estimates the have stolen the money in attacks carried out on 100s of banks since 2013. The gang took between two and four months on average to attack each bank and stole up to $10m from each.

Kaspersky Lab said it has seen evidence of $300m in theft through clients, and believes the actual total could be triple that.

Banks in 30 countries including Russia, the US, Germany, China and Canada were hit by the attack, which is thought to be one of the largest bank thefts ever.

"These bank heists were surprising because it made no difference to the criminals what software the banks were using," said Kaspersky Lab's principal security researcher, Sergey Golovanov. "It was a very slick and professional cyber robbery."

In the attacks, the criminals stole money directly from banks in contrast to the previous method of targeting customers, according to Kaspersky. They used malware that enabled them to see and record everything that happened on staff's computer monitors.

Subsequently, they programmed ATMs to dispense cash automatically at pre-defined times, and set up fake accounts to transfer money.

The criminal gang has been dubbed Carbanak after the name of the malware it has been using in its attacks.