Cracker tries to scan ports to find out which of them are open.
Because the administrator of computer can enter the hacker's Internet
protocol (IP) address into the suspect list, that is why cracker's
find , it is wise to conduct scanning from computer other than his
own. To this end, crackers set up Web sites on free servers (Free Web
Hosting providers) that allow them to use PHP and PERL scripts. Free
Servers (Free Web Hosting Providers) usually do not require personal
data to be provided during the registration, but even if they do,
cracker can simply supply and made up data because no one is going to
check them.