What is Virus?

Understanding Virus

A self-replicating program segment that attaches itself to an application program or other executable system component and leaves no external signs of its presence. A virus is malicious code that attaches itself to host programs or files and replicates by infecting other files or systems when the host program is executed. Viruses require some form of user action to initially spread and can damage systems delete files corrupt data or enable unauthorized access. Unlike worms viruses require a host program to propagate. Virus threats are addressed in standards like NIST SP 800-83 and various security frameworks. Organizations protect against viruses through anti-malware solutions email scanning application whitelisting user awareness and endpoint protection. For example an enterprise might defend against viruses by implementing layered protections including behavior-based anti-malware on all endpoints email gateway scanning to detect virus-laden attachments USB port controls to prevent infection via removable media application allow-listing to prevent unauthorized code execution and security awareness training teaching users to recognize social engineering tactics used to distribute infected files. Related terms Malware Anti-virus File infector Boot sector virus Macro virus Polymorphic virus Malware detection Signature detection Malicious code Payload.