• Detection by FortiGate units is a generic one, thus when your FortiGate unit displays "MTE_Family", it is refering to any one in a group of viruses within the Mutation Engine family
  • A mutation engine such as MtE or TPE is not a virus. It is a method. It enables a virus author to make an otherwise static & unchanging virus in to a virus that is polymorphic -- or ever-changing.
  • The act of linking the object file of a mutation engine to the code of an otherwise static virus is commonly referred to as giving a virus the characteristic of polymorphism.
  • Viral body is a variable number of bytes from infection to infection, and is usually appended, prepended or inserted (also referred to as a cavity virus) on or in to its host files
  • Virus runs memory resident and is often both polymorphic and encrypted
  • Target files can be .COM and .EXE for the known DOS polymorphic viruses.
  • There are several known families of polymorphic viruses, including:
    Engine Name
    MtE Dedicated
    TPE Girafe
    NED Ishtard

  • Other known DOS polymorphic viruses include Cruncher, Starship & Tremor