Bombtrack

Classification

Malware

Virus

-

Bombtrack, Gennops

Summary

BombTrack, a heavily armoured polymorphic virus, was distributed in BBS systems in the spring of 1994. It was hidden within the player for an erotic animation. Bombtrack is a memory-resident COM and EXE infector, about 2400 bytes long. It allocates 6 kB of DOS memory at runtime and infects executables when they are run. The virus achieves polymorphism by using variable decryptors buried in long runs of non-significant instructions. The virus uses a lot of anti-debugging tricks to prevent disassembly.

Automatic action

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.

Suspect a file is incorrectly detected (a False Positive)?

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 detection database 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.

For more Support

Knowledge Base

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User Guide

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Contact Support

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Submit a sample

Submit a file or URL for further analysis.

Technical Details

Before infection, the virus erases the MSAV and CPAV checksum files. It also carefully avoids infecting popular anti-virus scanners.

The virus contains several bugs. Some variants are not able to reproduce reliably and are, from a virocentric point of view, an evolutionary dead end. The activation routine is supposed to create a directory structure called "\BOMBTRA.CK\NEVER"ne". However, this operation is rather poorly implemented and almost always causes severe file system corruption.

The virus will sometimes infect an executable and fail to modify its entry point. Such files, at first sight similar to successfully infected ones, are not functional since the viral code never gets the chance to be executed. Finally, the virus doesn't take great care of the target's memory requirements: an infected COM file can grow to more than 64 KB and an infected EXE can grow larger than the memory it allocates. Such files are, unable to execute properly.

Bombtrack was the first Belgiƫan polymorphic virus.


Variant:Bombtrack.B

Slightly modified variant.