Russia's central bank said on Wednesday it had detected a cyber attack on Tuesday that used malware similar to the WannaCry and Petya encryptor viruses.
The bank said its centre for monitoring and reacting to computer attacks had sent out instructions to companies on how to detect and counter the malware.
It said it had found isolated cases of infection as a result of the attack, but that the consequences were quickly dealt with. It added that some institutions were still receiving infected files.