virus in unix/linux ...?

hi,

my questions are:
1). Is it possible to write virus programs on unix or linux environments?
2).if no why? technical answers....
3).is it right? "It is not possible to write virus programs in open source environments"

inventsekar

I think your assumptions are bad. Linux viruses exist:

http://www.viruslist.com/en/viruslistfind.html?findWhere=011&findTxt=linux

A virus is an exploit, which is theoretically possible anyplace where C or C++ code is run.

If you're actually interested check out Jack Koziol - "Shellcoder's Handbook"

hi,

till now i thought that it is impossible unix and linux environments.

and when unix and linux environments have virus like others how these are secure?

is unix and linux really secure than the others? (is unix and linux are same in security or unix is secure than linux?)