A trap door is hidden software or hardware mechanism that permits system protection mechanisms to be circumvented.
A virus is a program that can “infect” other programs by modifying them. Modification includes a copy of the virus program, which may infect other programs. Computer virus has similarity with biological virus, a biological virus infects the machinery [...]
An intrusion detection system (IDS) monitors network traffic and monitors for suspicious activity and alerts the system or network administrator. In some cases the IDS may also respond to anomalous or malicious traffic by taking action such as blocking the user or source IP address from accessing the network.
IDS come in a variety of “flavors” [...]
Using vulnerability scanners to regularly test for potential exploits is a strong addition to other security defenses such as firewalls and intrusion detection and prevention systems, but it’s not as simple as launching the scan and then assuming everything is taken care of.
Users have to accurately interpret scan results, make sure the database the scanners [...]
Statistical anomaly based IDS- A statistical anomaly-based IDS establishes a performance baseline based on normal network traffic evaluations. It will then sample current network traffic activity to this baseline in order to detect whether or not it is within baseline parameters. If the sampled traffic is outside baseline parameters, an alarm will be triggered.
Signature-based IDS- [...]