Classification

Category :

Malware

Type :

Worm

Aliases :

Antinny, W32.HLLW.Antinny

Summary

This worm will spread though the P2P network of the Japanese software Winny P2P. The file length is 651264.

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

When the worm is executed it will display a fake error Window with Japanese text.

The worm incorporates DLLs within its body, with the purpose of handling LHA and ZIP compressed files. Those DLLs amount for most of the worm's length.

The DLLs will be copied to the Windows' system folder. Their names and lengths follow:

UNLHA32.DLL, 254.464 bytes
zip32.dll,
 135.168 bytes
ZIP32J.DLL,
 61.440 bytes
 

all of those components are harmless by themselves.

The worm copies itself to the Windows' system folder, the full path of the file is:

%WinSysDir%\ny.exe
 

and an entry in the Windows' Registry is added, aiming at having the worm start when Windows does.

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\run]

"ara-key" = %WinSysDir%\ny.exe -StartUp
 

It will then copy itself again, with the same name "ny.exe", to the user's default folder for temporary files.

The worm will attempt to find the Winny P2P software by searching the system for the application's main executable "Winny.exe", once found it will copy itself to the folder designated by the user as the one containing shared content. This will make the worm available for download to other users of the P2P network.