A lot of webmaster give first preference for security. They don't want to have their whole work damaged by one silly mistake and then spend a lot of time to fix it. Using pirated software, themes and plugin can be a red carpet for hackers. Sadly, that is not the only one. There are many ways your server space be can be compromised. What will you do when something like that happens ?
I will, if my skill provides will go through the files and database and see which part has been compromised. Remove the bad code and try to get back to where I was.
But that might not work all the time. You need to find out how the hacker got inside. In such case, the troublemaker or his auto running script can come back and hit you again.