Details (Kaspersky Labs): It is not a dangerous memory resident parasitic virus. It hooks INT 21h and writes itself to the end of COM and EXE files that are executed. In one month after infecting the virus also hooks INT 8,9 and manifests itself by a video effect.
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Virus.DOS.Lichen.1024 or Lichen is a virus that runs on MS-DOS. Lichen is not a dangerous memory...