In all cases a hacker is someone with deep knowledge of computer systems, networking, software and hardware architecture, and is usually also a very knowledgeable person...
Computer systems and computer networks are important resources whose safety and integrity are important. Hacking is defined as a process or occupation wherein a person tries to gain unauthorized access to a system. The reasons might be various. Some are just unsure about the legality of the process, and assume they are doing nothing illegal. Some get satisfaction in being able to crack into a system. Some want to cause malicious harm. Some plan to achieve financial rewards. In all cases a hacker is someone with deep knowledge of computer systems, networking, software and hardware architecture, and is usually also a very knowledgeable person.
There are various associated terms with varying meanings, like a Black-Hat (bad hacker), White-Hat (ethical hacker), cracker (usually working on software hacking and not network hacking), Grey-Hat, etc. The hacker makes use of a number of tools, like Trojan Horse (a dissembling program), virus (self replicating malicious program), worm, vulnerability scanner (scanning of empty ports or firewall loopholes), sniffer (sniffing of password and other important data while in transit), exploit (prepared application to take advantage of known weaknesses), social engineering (inveigling information from legitimate user), root kit (hiding of intrusion trails), etc.
Hacking is a worldwide menace resulting in loss of millions of dollars. Intrusion into systems, theft of sensitive data, direct theft of financial resources through impersonation, creating denial-of-service (DoS) attacks and causing online nuisance by squatting on websites – actions like these affect all. Legislation is being made around the world to deal with these new penal areas. Security systems are being buttressed to deal with hacker attacks, and anti-virus programs and firewalls are updating themselves to deal with the latest invention of the sick mind.
This section of the directory provides links to various resources related to fighting hacking, like tools for ethical hacking to other informational literature.