One of the first network security tools was the intrusion detection system (IDS), first developed by SRI International in 1984. An IDS provides real-time detection of certain types of attacks while they are in progress. This detection allows network professionals to more quickly mitigate the negative impact of these attacks on network devices and users. In the late 1990s, the intrusion prevention system or sensor (IPS) began to replace the IDS solution. IPS devices enable the detection of malicious activity and have the ability to automatically block the attack in real-time. In addition to IDS and IPS solutions, firewalls were developed to prevent undesirable traffic from entering prescribed areas within a network, thereby providing perimeter security. In 1988, Digital Equipment Corporation (DEC) created the first network firewall in the form of a packet filter. In 1989, AT&T Bell Laboratories developed the first stateful firewall. 3. Security threats End user computers could be exposed to a multitude of threats anytime because they are very vulnerable without any implemented security measures. They could affect also the computers’ employees within an organization when no network security policies are applied. Security threats can be categorized as it follows: • Virus • Worm • Trojan Horse …show more content…
They require end-user activation and can stay dormant for a period of time before activating. A less complex virus may install itself after running the first line of code on an executable. Once it is activated, it will look for other files in order to multiply, such that all the files will become infected. Depending on the virus, there are harmless as the ones displaying a picture on the screen or can be destructive as those that modify and delete files on the hard drive. Very complex viruses cannot be detected because they are programmed to