What is it?
Spybot Search & Destroy - sdhelper.dll

What does it do?
Spybot S&D resident IE protection, bad download blocker (BHO) Source:

Virus Precautions:
You'll want to keep an eye on this google search for any known viruses. The normal location of this file is C:Program FilesSpybot - Search & DestroySDHelper.dll


Also .