Virus is a program which is able to replicate with little or no user intervention,
and the replicated program(s) are able to replicate further. Writing a good virus is
challenging, the best viruses are written in C language, and building as executable
file from C source code to plant virus code into another executable. The result either
prohibitively large, or very dependent on the completeness of the target installation.
Real viruses approach the problem from the other end. They are aggressively
optimized for code size and do only what's absolutely necessary. However, this has
some limitations and the solution to these limitations is complicated and makes the
virus more likely to fail. This paper presents a design and implementation of a virus
running on Linux operating system as Loadable kernel module (LKM) to overcome
the limitations of developing the virus as C program. This virus can infect Linux
modules in addition to executable files.