RoboForm.dll is a part of the Roboform software and it helps you automated the process of filling out forms. a typical HJT log will look like this:

O2 - BHO: (no name) - {724d43a9-0d85-11d4-9908-00400523e39a} - D:Program FilesSiber SystemsAI RoboFormRoboForm.dll