Sberbank, along with four other institutions, experienced distributed denial of service (DDoS) attacks on Tuesday and through the night into Wednesday before they subsided. The hackers failed to get their hands on bank funds during the attacks. Russian authorities have yet to identify any of the perpetrators.
Russian financial institutions Alfa Bank, Moscow Bank, Rosbank and the Moscow Exchange faced similar attacks on Tuesday, according to Russian state news agency TASS.
Typical DDoS attacks involve hackers overloading target servers with fake Internet traffic until they collapse, shutting down genuine business activity.
The attacks on the financial institutions have been traced to machines in 30 countries including the US, India, Taiwan and Israel, with each attack lasting from one to 12 hours, Russian news outlet RBC reported.
The attacks were largely unsuccessful in disrupting usual financial services and customers’ information was not compromised, bank officials told state media.
Sberbank plans to work with the security teams of the other banks involved and law enforcement to determine who organized the attacks, according to chairman Stanislav Kuznetsov.
The last major series of DDoS attacks on banks was in October 2015, when eight Russian banks were targeted.
 "These kind of attacks happen, for us this is attack 68," Kuznetsov told Russian state media. He declined to speculate on a motive for the attacks.
