MOSCOW: The old KGB is back with an offer many Russians can't refuse. Just pick up the phone, dial 224-3500, and confess you're a spy. Agree to become a double agent, and Mother Russia will pay you twice what you were getting before (a bold claim in a country where even the soldiers haven't been paid in months). The plan is to get a little back from the foreign spy agencies who have swooped into Russia since the fall of the Soviet Union, scooping up precious military secrets from Russians for a song. So far, the boys working the Lubyanka hotline say the response has been fantastic. Several hundred "interesting" phone calls (as well as a few "psychologically abnormal" ones) have poured in since Nikolai Kovalyov, head of the KGB's successor, the Federal Security Service, went public in a recent televised appeal.