A Computer virus :
A Computer virus is a computer program that affects and infects the computer. It can spread throughout the computer and from one computer to another. once a computer is infected by a virus, it damages the files, software and even the operating system.
Most of the computer viruses spread through removable media such as floppy disks. a virus is one of the cause of having a "hang" computer, and if it is not removed , it would corrupt and totally damage files and worst , viruses will spread widely and may over-power the computer world.
A worm :
A worm is a software made to disrupt computer operation and gain unauthorized access to a computer system.It exploit security and uses a computer network to replicate and copies of its self o other systems.At some point, researchers attempted to create a useful worm like the worm that utilizes topology information and Spanning Tree information stored in switches to probe for vulnerable nodes until the enterprise network is covered.Worms may at least cause harm to the network and does not need to attach itself to other programs unlike computer viruses.
A Trojan horse :A Trojan horse is sometimes confused with the worms even though they are totally different. a Trojan may harm the performance of a computer just like a computer worm does. but a Trojan appears harmless but rather hide a malicious function. It does not intend to infect files and replicate itself to infect other computers but Trojan horses makes copies of themselves, steal information, and harm host computer systems. it is called a Trojan horse because it appears to be a helpful program, but the truth is they are often destructive programs that masquerade as benign applications.
A Payload :
Payload is a body data in a data transmission. It is the part of the transmitted data which is the fundamental purpose of the transmission, to the exclusion of information sent with it such as overhead data, solely to facilitate delivery.
Honeypots :
a honeypot is a trap made to detect, deflect, and in some manner counteract attempts at unauthorized use of information system. It is commonly used by companies and corporations to improve their over-all state of security.Honeypots are made against spammers,detection systems are spammer-employed counter-weapons.
A Bot-nets :
A bot-net is a collection of computers connected to the internet. When a computer is compromised by an attacker, there is often code that commands it to become part of a botnet. The "botmaster" or "bot herder" controls these compromised computers via standards based network protocols. Bot-nets are exploited for various purposes.
Spoofing :
a spoofing attack is a situation wherein a program successfully hides as another by falsifying data and thereby gaining an illegitimate advantage.It is also called the copyright holders placing distorted versions of works on file-sharing networks, to discourage downloading from these sources.
Denial service attack :
A denial-of-service attack (DoS attack) is an attempt to make a computer network resource unavailable to its intended users.It is consists of the efforts of a person or multiple people to prevent a service from functioning efficiently or at all, temporarily or indefinitely.
Back door :
a back door is a program that allows users to bypass security controls when accessing a program, computer or a network.
Firewall :
A firewall is a device made to permit or deny network transmissions based on a set of rules and is frequently used to protect networks from unauthorized access while permitting legitimate communications to pass.it is referred to wall intended to confine a fire or potential fire within a building.the hosts protected behind a firewall commonly have addresses in the "private address range".
