Based on source of  Netbull

Written in Visual C++

Released in september 2003

Made in China

Server:
c:\WINDOWS\SYSTEM\CheckDll.exe 

size: 50.688 bytes
 
port: 23444 TCP

startup:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run "CheckDll.exe" 
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunServices 

added:
c:\infected.exe