Computer Virus

A computer virus[1] is a type of computer program that, when executed, replicates itself by modifying other computer programs and inserting its own code.[2][3] If this replication succeeds, the affected areas are then said to be "infected" with a computer virus, a metaphor derived from biological viruses.[

Computer viruses generally require a host program.[2] The virus writes its own code into the host program. When the program runs, the written virus program is executed first, causing infection and damage