Threat Descriptons



Category :


Type :


Aliases :

Trojan:W32/Krap.B, Packed:W32/nsanti.gen!c, Packed.Win32.Krap.b, Packer.Malware.NSAnti.1


Trojan:W32/Krap.B identifies software that has been packed with a particular Packer program known to be frequently used to compress malicious files.


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 packer is custom made and has been designed to protect packed files from being debugged, emulated, or unpacked. The code in the packer stub is difficult to read and analyze since it has been obfuscated quite well. There are many decryption loops for the packer code itself which it executes during runtime and the code seems to be polymorphic.The contents of the packed files are usually password stealers for onlinegames. They may also include some other types of malware such as trojans and worms.

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