We’ve covered that BlackSheep Firefox extension detects and alerts users if anyone is using Firesheep on your wireless or open networks, to install BlackSheep extension you first need to install wincap in your Computer. If you have installed BlackSheep for Firefox, you may observe firesheep-backend.exe running in the task manager.
We don’t know if with the use of Firesheep, firesheep-backend.exe process runs in background, since we’ve not tested it, neither we’re going to recommend users to use it to hack twitter and Facebook user accounts, it is illegal also.
I confirmed by disabling and uninstalling BlackSheep extension that if you’re not using firesheep and installed Blacksheep to protect from Firesheep then Firesheep-backend.exe process will appear running in the task manager.
BlackSheep is based on code of firesheep, it works by sending fake cookie values for every 5 minutes for Firesheep. The only way you can stop firesheep-backend.exe process from running is by uninstalling BlackSheep add-on.