Threat Descriptions

Gop (worm)

Classification

Category :

Malware

Type :

Worm

Platform :

W32

Aliases :

Gop (worm), I-Worm.GOPworm, W32/Invery.A@mm, Invery

Summary

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++.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

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: 

HKCR\exefile\shell\open\command

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.