A computer virus is a type of malicious software or program that, when executed, replicates itself by modifying other computer programs and inserting its own code. When this replication succeeds, the affected areas are then said to be "infected" with a computer virus or malware.

Each malware is created for a unique purpose. Most viruses can be prevented or remedied with the use of Firewall or Anti-virus software, however, few viruses are irrecuperable to an extent that it destroys the core system.