Moscow, February 17 (RHC)-- Russian computer security firm Kaspersky Lab says cyber criminals have robbed as much as $1 billion (870 million euros) from banks around the globe in a wave of cyberattacks that started in 2013 and are still going on.

Kaspersky says the large-scale theft "indicates clearly the coming of a new era for cybercrime." About 100 banks -- mainly in Russia but also in the United States, Germany, China and Ukraine -- have been targeted, the company announced in a statement to the media.

It was too early to pin down the source of the attacks, although some evidence points to China, Kaspersky said, while warning that hackers sometimes plant clues intended to mislead investigators. The goal of the attacks "appears to be financial gain rather than espionage," the company said, adding that the attackers are "clearly familiar with the software and networks of financial services."

Hackers commonly break into bank networks by tricking staff into clicking on links or email attachments in a process called "phishing." In some cases the hackers follow targeted employees on video surveillance images. Once the attackers are in, they can then transfer money to accounts under their control or make withdrawals at certain bank machines. Stolen money was transferred to the United States and China, Kaspersky said.

Hackers had such advanced access to the banks' systems that they could force bank machines to dispense cash at specific times and locations where hackers could pick it up, The New York Times reported. Whopping sums of cash were involved, with one institution losing $7.3 million in withdrawals at bank machines as well as $10 million more through its online platform.