What does this shell command do in Linux
:(){ :|: & };:
How can it be used in Denial of Service attacks?
Answer
It's a fork bomb. I actually have that written on my whiteboard (as a joke) as I speak. Don't run it.
:() # define a function named :, () defines a function in bash
{
: | :; # the pipe needs two instances of this function, which forks two shells
}
; # end function definition
: # run it
So, the first run makes 2 subshells, which then each runs 2 more subshells...
: is a built in command in bash. It's kind of a "null" no-op command. It used to be the comment character, before there was a comment character. Now, it's got a small use as a no-op, but really used here because it's more cryptic, you look at :()
and think WTH is that?
No comments:
Post a Comment