Threat Descriptions

Linux/Staog

Classification

Category :

Malware

Type :

Virus

Platform :

Linux

Aliases :

Linux/Staog, Staog

Summary

This virus spreads only under Linux operating system, infecting Elf-style executables. Found in the fall of 1996, Staog is the first known Linux virus.

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

Staog is written in assembler. It attempts to stay resident and infect binaries as they are executed by any user. Stoag tries to subvert root access via three known vulnerabilities (mount buffer overflow, tip buffer overflow and one suidperl bug).

Staog contains several text strings, including:

Staog by Quantum / VLAD

 /dev/kmemx/etc/mtab~

 /sbin/mount

 /tmp/t.dip

 /bin/sh

 /sbin/dip /tmp/t.dip
 chatkey

 /tmp/hs
 
		 #!/bin/sh\nchmod 666 /dev/kmem\n/tmp/hs
 
		 #!/usr/bin/suidperl -U\n$ENV{PATH}=\"/bin:/usr/bin\";
 
		 \n$ =0;$ =0;\nexec(\"chmod 666 /dev/kmem\");\n

VLAD is an Australian virus group, which also wrote the first Windows 95 virus, Boza.Staog can be detected by searching all binaries for the following hex search string: 

215B31C966B9FF0131C0884309884314B00FCD80

Staog is not known to be in the wild at the time of this writing (February 1997).