Polymorphic virus

Virus that re-encrypts itself with each infection

A polymorphic virus is one that encrypts its code differently with each infection, or generation of infections.

The aim of this behaviour is to make it difficult for anti-malware software to detect all files infected with the virus, requiring much more sophisticated detection techniques than simple file-infecting viruses, which insert their code unchanged into each infected file.

The same term is often also used to cover metamorphic viruses.

Quick Links

Should software vendors extend support for their products on Windows XP beyond the end-of-life of the operating system?
Yes - it keeps their users secure
No - it encourages users to continue to use a less secure OS
I don't know
Leave a comment
View 24 comments

SMI Oil and Gas Cyber Security 2014

Virus Bulletin
In this month's magazine:
  • VBSpam comparative review March 2014
  • VB100 comparative review on Ubuntu Server 12.04LTS
  • The shape of things to come
  • Threat intelligence sharing: tying one hand behind our backs
  • The curse of Necurs, part 1
  • More fast or more dirty?
  • Tofsee botnet
  • Back to VBA
  • Is the security industry up to the new challenges to come?
  • Greetz from academe: No place to Hyde
Virus Bulletin 04 2014
Subscribe now!

Virus Bulletin currently has 231,305 registered users.