Troj/CoreFl-Gen is a family of backdoor Trojans.
Typically Trojans drop a randomly named DLL file in the Temp folder. A copy of this is made in the Windows system folder with a random filename and a DIL file extension. The Trojan also drops multiple DAT files with randomly generated names.
Registry entries of the following form are created in order to run the malware on startup:
HKCR\CLSID\{<randomly generated GUID>}\InprocServer32
(default)
<System>\<path to Trojan>