We have covered that BlackSheep Firefox extension detects and alerts users if someone is using Firesheep on their wireless or open networks, to install BlackSheep extension you first need to install wincap on your computer. If you have installed BlackSheep for Firefox, you may notice firesheep-backend.exe running in task manager.
We don’t know if with using Firesheep, the firesheep-backend.exe process runs in the background as we have not tested it, nor do we recommend users to use it to hack Twitter and Facebook user accounts, it is also illegal.
I confirmed by disabling and uninstalling the BlackSheep extension that if you are not using firesheep and installed Blacksheep to protect from Firesheep, Firesheep-backend.exe process will appear running in the task manager.
BlackSheep is based on firesheep code, it works by sending fake cookie values every 5 minutes to Firesheep. the only way you can stop firesheep-backend.exe process execution is by uninstalling the BlackSheep add-on.