Hacking methods

Footprinting : Before a hacker attempts to gain access to a system, time will be spent gathering information about the target - domain, network blocks, IP addresses and system architecture. A good system has multi layer security. Hacker has to go through the organization's website (html source code), whois lookup, nslookup for domain tables, searching information via anonymous FTP sites, network protocol used etc.

The site maybe linked to an unsecured site. Hackers will use this security
loophole and crack the main site. Social engineering is used to get access to the system by contacting users (employees) and even the sysadmin. This is a powerful technique commonly used. Through specific queries to DN registrar, potential info will be collected from www.internic.net

To prevent hacking, deny DNS zone transfer (using 'nslookup'). Set firewall or router to deny all unauthorized inbound connections to TCP port 53. A hacker can discover the network topology of a target network as well as access control devices using 'traceroute'. 'traceloop' gives the traffic return path information.