Guys there are many other methods for hacking...even a completely secure script can be hacked...
It happened with me few weeks ago that a trojan came into my computer...and somehow copied my ftp account details while i was working through ftp. Then it added some coded script to all pages with names index.xxx, home.xxx and default.xxx . The task of the script was to download malware softwares to those computers which opened my site. Changing the ftp password and removing that script solved the issue...
But see more notice that it had copied my ftp details. So it could do anything with site files.
So guys be updated about various hacks...and try to avoid them.