Computer Viruses and Environmental Hazards
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Viruses are programs that infect other programs by attaching themselves and executing their code without the user's knowledge. They have destructive behavior, rely on hosts to survive and spread, can protect themselves from detection and removal, and come in many forms. Viruses have two phases - an infection phase where they infect other programs each time they are executed or upon a certain trigger, and a payload phase where they carry out their intended harmful actions. Some viruses reside in memory like terminate-and-stay-resident programs to wait for events like inserting disks or copying files to infect other programs, making them difficult to detect.
Computer Viruses and Environmental Hazards
- 2. Computer Viruses and Environmental Hazards
- 4. Name of the Group Members Md. Selim Reza Bappy
- 5. Computer Viruses and Infest stations VIRUS stands for Valuable Information Resources Under Seize. A virus is a program which produces its own code by attacking itself to other programs in such a way that the virus code is executed. In other words, Viruses are programs that share some or all of the following characteristics with real viruses: They have destructive behavior. They rely on a host to survive and spread. Executing the host program will also activate the virus program, without the user knowing. They can protect themselves. They can protect themselves against attempts to detect and remove them. Not all viruses have all these characteristics because virus technology changes to fast.
- 6. Viruses come in many different forms, but they all potentially have two phases to their execution: Infection Phases When the virus executes, it will infect other programs. Some viruses Infect other programs each time they are executed; others infect only upon a certain trigger. This trigger could be anything-a day or time, an external event on the pc or a counter within the virus. Many viruses reside the memory of the pc just as terminate-and-stay- resident(TSR) program that is loaded into memory but is not immediately executed, such as screen saver. This means that the viruses can wait for some external event such as inserting a diskette, copying a file or executing a program to actually infect another program. These viruses are very dangerous since it is hard to guess what trigger condition they use for their infection. Resident viruses frequently corrupt the system software on the pc to hide their existence.