Security experts warn that one day you may get unexpected alert reporting Unknown Win32/Trojan found on your computer. Some of such alerts may even have a title with Microsoft Security Essentials name but they are not legitimate! Unknown Win32/Trojan is reported by FAKE MSE and ‘detected’ with the only reason to make you concerned about your computer and then push you into purchasing the rogue.
The trick about Unknown Win32/Trojan is that users are offered to purchase ‘licensed’ software which is promised to remove this nonexistent trojan. However, every time Unknown Win32/Trojan is announced, a different anti-malware is offered for its removal. And you should have heard about Windows Easy Warden or Windows Armour Master that have been promised to help with Unknown Win32/Trojan removal.
We highly recommend you running a reputable anti-spyware (STOPzilla recommended) to fix your PC from dangerous trojans that mislead users about Unknown Win32/Trojan detection.