90% of hackers are teens and amatures, just wanna show their muscles and say " ADMIN WE HACKED YOU, GO TO HELL" and so on
so if you wanna keep yourself safe
-Always keep tracking new exploits for your script and fix it
you can find daily updated exploits here
www.exploit-db.com/
+ do not wait to be hacked and then try to fix it
-hire professional security expert ( Like me :P
) )
-protect your php code from mysql injections, using some simple php coding or functions like mysql_real_escape_string() or adslashes or so
-take daily backups
-always take a look at your visitors stats
-block unwanted IPS or previous attackers ips
-use DDos protected hosting
hope that helps
Thanks