When the host code is executed, the virus code is executed as well.
Viruses can range in severity from causing mildly annoying effects to damaging data or software and causing denial-of-service (DoS) conditions.Īlmost all viruses are attached to an executable file, which means the virus may exist on a system but will not be active or able to spread until a user runs or opens the malicious host file or program. It spreads from one computer to another, leaving infections as it travels. Viruses, worms, Trojans, and bots are all part of a class of software called malware.Ī computer virus propagates by inserting a copy of itself into and becoming part of another program. The expression is a general term used by computer professionals to mean a variety of forms of hostile, intrusive, or annoying software or program code. It is a combination of the words malicious and software. Malware is software that is designed to infiltrate or damage a computer system without the owner's informed consent.
