The Bank of Russia's Web site was taken down by hackers on Friday ahead of a meeting on interest rates.
In a statement, the central bank says: "Currently the bank of Russia website is having troubles due to a hacker attack. The bank of Russia is taking measures to rebuff it and to restore normal operation."
The official Kremlin Web site has also been hit by attackers throughout the morning.
The central bank decided to keep interest rates unchanged after unexpectedly raising them two weeks ago in a bid to halt the decline of the ruble amid the Ukraine/Crimea crisis.