By Andrew Osborn
MOSCOW (Reuters) - Russia's FSB security service said on Wednesday it had helped detain a gang of about 50 hackers who stole over 1.7 billion roubles ($25.33 million) from the accounts of various Russian financial institutions.
The same gang had tried to steal a further 2.273 billion roubles by issuing false payment instructions which had been blocked, the interior ministry said.
The suspects had used malware to set up a network of bots on infected computers to carry out the cyber attacks, the ministry said, and Sberbank, Russia's largest bank by assets, had helped the authorities crack the case.
The hackers targeted accounts belonging to corporate entities as well as correspondent accounts belonging to financial institutions. The authorities did not name any other lenders apart from Sberbank or say how many accounts had been compromised.
About 50 individuals were detained in nationwide raids as part of the investigation, 18 of whom were now behind bars in Moscow pending the outcome of the case, according to the FSB.
A criminal case into the matter has been opened accusing those arrested of being part of an organized criminal group and of using computers to perpetrate fraud.
Footage of the raids in 15 different Russian regions showed armed men wearing balaclavas using battering rams to gain access to properties and handcuffed men later being unloaded from a van.
"As a result of (house) searches a large quantity of computer equipment was confiscated along with communications gear, bank cards in false names, and also financial documents and significant amounts of cash confirming the illegal nature of their activity," the FSB said in a statement.
The FSB, the successor to the Soviet KGB, said it had carried out the operation with the interior ministry backed by armed units of the National Guard.
The interior ministry said it had registered 18 cyber attacks on lenders since the middle of last year which had resulted in total losses of over 3 billion roubles ($44.70 million).
(Editing by Alexander Winning)