Troj/Nebule-B is a Trojan for the Windows platform.
Troj/Nebule-B drops a malicious dll into the System folder when executed, for example:
<System>\winxyl32.dll (also detected as Troj/Nebule-B)
The following Registry entries are set to subsequently load the malicious code in this dll into other processes.
HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\winxyl32
Dllname
<System>\winxyl32.dll
HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\winxyl32
Startup
<exported_functionname_within_dll>
HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\winxyl32
Shutdown
<exported_functionname_within_dll>