Ethical hackers are up against several individuals in the battle to secure the network. The following list presents some of the more commonly used terms for these attackers

• Phreakers – The original hackers. These individuals hacked telecommunication and PBX systems to explore the capabilities and make free phone calls. Their activities include physical theft, stolen calling cards, access to telecommunication services, reprogramming of telecommunications equipment, and compromising userids and passwords to gain unauthorized use of facilities, such as phone systems and voice mail.

• Script/Click Kiddies – A term used to describe often younger attackers who use widely available freeware vulnerability assessment tools and hacking tools that are designed for attacking purposes only. These attackers typically do not have any programming or hacking skills and, given the technique used by most of these tools, can be defended against with the proper security controls and risk mitigation strategies.

• Disgruntled employee – Employees who have lost respect and integrity for the employer. These individuals might or might not have more skills than the script kiddies. Many times, their rage and anger blind them. They rank as a potentially high risk because they have insider status, especially if access rights and privileges were provided or managed by the individual.

• Whackers – Whackers are typically newbie who focus their limited skills and abilities on attacking wireless LANs and WANs.

• Software Cracker/Hacker – Individuals who have skills in reverse engineering software programs and, in particular, licensing registration keys used by software vendors when installing software onto workstations or servers. Although many individuals are eager to partake of their services, anyone who downloads programs with cracked registration keys are breaking the law and can be a greater potential risk and subject to malicious code and malicious software threats that might have been injected into the code.

• Cyber-Terrorists/Cyber-Criminals – An increasing category of threat that can be used to describe individuals or groups of individuals who are typically funded to conduct clandestine or espionage activities on governments, corporations, and individuals in an unlawful manner. These individuals are typically engaged in sponsored acts of defacement; DoS/DDoS attacks identify theft, financial theft, or worse, compromising critical infrastructures in countries, such as nuclear power plants, electric plants, water plants, and so on.

• System Cracker/Hacker – Elite hackers who have specific expertise in attacking vulnerabilities of systems and networks by targeting operating systems. These individuals get the most attention and media coverage because of the globally affected viruses, worms, and Trojans that are created by System Crackers/Hackers. System Cracker/Hackers perform interactive probing activities to exploit security defects and security flaws in network operating systems and protocols