Category: Malware

Type: Virus

Aliases: S-Bug, SatanBug


S-Bug is a highly polymorphic virus that has been reported to be in the wild in USA and in several other locations.

Virus stays resident in memory occupying 9 KB's of DOS memory. It hooks the following INT 21h functions: 3Dh, 4Bh, and 6Ch. Infected files grow in size between 4k and 5k bytes.

Infected EXE and overlay files may fail to execute correctly. Virus includes string "Satan Bug virus - Little Loc".

The virus will only become resident if the environment variable COMSPEC= is set to point to a file called COMMAND.COM.

S-Bug virus also removes validation codes added to files by McAfee SCAN and CPAV's Immunize function.


Automatic action

Based on the settings of your F-Secure security product, it will either automatically delete, quarantine or rename the detected program or file, or ask you for a desired action.

Knowledge Base

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About the product

See the manual for your F-Secure product on the Help Center.

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Submit a sample

Submit a file or URL for further analysis.

Technical Details


A related variant. Uses similar encryption, but the actual virus is simpler and non-resident.

See: Natas