The attack is an attempt to destroy, expose, alter, disable, steal or gain unauthorized access to or make unauthorized use of an asset.
- Intruder access unauthorized information from a computer system but cannot cause harm to the system.
- Browsing: Intruders here attempt to read stored files, traverse message packet on the network, access other process memory, etc.
- Inferencing: The intruder records and analyzes past activities and access methods and uses this information to draw inferences.
- Masquerading: An intruder Masquerades as an authorized user or a program to gain access to unauthorized data or resource.
- The virus a small computer program that needs to executed by either running it or having it loaded from the boot sector of a disk.
- The worm is a small piece of software the uses computer network and security holes to replicate itself.
- A logic bomb a piece of code intentionally inserted into a software system that will set off a malicious function when specified conditions met.
- Integrity attack: An intruder can change the message. While it is traveling in the communication channel and the receiver may interpret it as the original message.
- Authenticity attack: An intruder can illegally connect to the computer network, impersonate and insert bogus message with the valid address in the system. These will then delivered a genuine message.
- Denial attack: An intruder might partly or completely block communication path between two processes.
- Delay attack: An intruder can delay the message delivery that can make it useless to receive if it received late.
- Replay attack: An intruder retransmits an old message that accepted as a new message by the receiver.