Troj/BHO-EU is a Trojan for the Windows platform.
When Troj/BHO-EU is installed it creates the file <System>\<random characters>.dll.
The above mentioned file is registered as a COM object and Browser Helper Object (BHO) for Microsoft Internet Explorer, creating registry entries under:
HKCR\CLSID\{Random GUID}
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{Random GUID