Gop is a worm that spreads via the Internet being attached to infected emails and through local network by copying to shared drives. The worm itself is a Windows PE EXE file about 60Kb of length (compressed by UPX), written in Delphi Microsoft Visual C++.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
The worm is improved variant of a password stealing trojan Trojan.PSW.GOP (trojan).
The infected messages Subject and Body are in Chinese. The attached file name is different, and has double extension:
filename.jpg.exe filename.jpeg.exe filename.gif.exe filename.txt.exe filename.doc.exe filename.rtf.exe filename.bmp.exe
To run from infected message the worm uses IFrame security breach.
While installing the worm uses the same way as "GOPtrojan", the additional feature is affected Registry key:
To send infected messages the worm uses direct access to a SMTP server. The worm gets victim email addresses by scanning *.HTML, *.HTM, *.JS files, as well as by scanning TheBat, Aerofox and RimArts email databases.
Technical Details: Kaspersky Labs; January 2002