The Lyublinsky Court found members of the gang guilty of manufacturing and trading false credit cards.
Group leader Artur Lyashenko, from the south Ukrainian city of Odessa, was sentenced to six years in prison and fined 10,000 rubles ($370).
His main accomplices, Muscovites Alexei Stroganov and Gerasim Selivanov, were given six and five and a half years, respectively.
Three others, Valentina Antipova, Alexei Ignatov, and Nikolai Steshenko, were given suspended five-year sentences.
The prosecution accused the defendants of making more than 5,000 false credit cards and selling them in Russia and abroad, advertising their services on the Internet.
The Russian Interior Ministry said Lyashenko had in many cases illegally obtained access to clients' banking and credit card information, which he passed on to buyers of the fake cards as an additional service. The buyers would then use the information to steal the maximum possible amounts from the legal account holders.