It is a dangerous nonmemory resident parasitic virus. It searches for .COM and C:COMMAND.COM files, then writes itself to the end of the file. Depending on the system timer it sets the graphic video mode (INT 10h, AX=0013h), displays the message and halts PC:
SYSTEM ERROR: DMA DENIED.
The virus also contains the text string:
c:command.com
*.com
NSD
