F-Secure Virus Descriptions : Linux/Staog

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.

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