The Russian Mafia, also known as the Mafiya is an organized crime syndicate that is similar to the Sicilian or Italian-American Mafia, only they're from Russia rather than Italy, Canada, or the United States. They commit many of the same crimes, including but not limited to drug dealing, gun running, money laundering, heists, bribery, contract killing, and cybercrime.
In Soviet times, the Russian mafia flourished in conjunction with the KGB. Both Western trade and financial NGOs (IMF, WTO, World Bank) and Soviet entities (COMECON) refused trade between the Western Powers and the Soviet bloc. The Russian mafia grew very rich and powerful smuggling foreign made consumer goods into the Soviet Union while paying bribes, kickbacks and a share of the profits to the KGB, which functioned as the Soviet border guard as well. Thus an unholy alliance between Russian organized crime and Soviet law enforcement was born which gave Soviet people and Communist party elite access to Western consumer goods which the socialist economy was incapable of producing.
When the Soviet Union collapsed, many ex-KGB found fulltime employment with their former partners in the Russian mafia, which had distribution networks for illegal goods throughout the former Soviet Union, including not only Western made consumer goods, but narcotics and human trafficking as well.