They employed various methods including: Organization of Terrain, Use of Artillery, Air Support, and Use of Antitank Rifles.

The PTRD-41 and PTRS-41 are the two anti-tank rifles fielded by the Red Army. Both rifles fire a round a little bigger then the .50 BMG that is capable of penetrating the side of German tanks and self propelled guns at close ranges. The Soviet soldier was also armed with the RPG-40, RPG-43, and RPG-6 Anti-Tank Grenades. All are hand thrown grenades, The Red Army never made or issued any magnetic anti-tank mines nor did any Allied County. The Germans were the only country to make magnetic mines [First issued in 1943] and actually feared other countries would copy them and began coating tanks in a plastic paste that prevented magnets from sticking to them.

Also here is a list of Soviet anti-tank tactics and how they would of been applied.