Rosneft sign
© Maxim Shemetov / Reuters
Russian oil giant Rosneft has said its servers came under a massive hacking attack, according to a statement on Twitter. The company has asked Russia's security services to look into the issue.

"We hope that it isn't connected to the current legal proceedings in any way," the company's statement said.

The latest announcement comes after a court froze some assets belonging to Russian businessman Vladimir Yevtushenkov's Sistema corporation as the result of a lawsuit filed in May by Rosneft and its subsidiary Bashneft, as well as Russia's Republic of Bashkortostan.

According to the Russian plaintiffs, Sistema took some $3 billion of the oil company's assets when it owned Bashneft from 2009 to 2014.