The file backbas.dll is part of 1C:Enterprise 8.1, an accounting system developed by the Russian company 1C. The 1C:Enterprise system is a business package that includes inventory management, documentation, accounting, and internet solutions. The system is used widely in Russia and the former Soviet states.
1C also markets video games, both original games and Russian translations of popular Western games. While it is unlikely that this file would get on your computer from running a game produced by 1C, dynamic link libraries are made to be shared among programs, so it is possible.
You are most likely to get this file as part of an error message if you are running 1C:Enterprise, and the file has been misplaced. To find out what happened to your file, run a free scan from ZookaWare PC Cleaner. The scan will tell you if you have problems that cleaning the registry will fix. Your computer will soon be running smoothly again.