It is not a dangerous memory resident parasitic encrypted virus. It hooks INT 21h, 28h, searches EXE files into current directory and writes itself to the end of them. It compares the file names with the strings:
ADIN DINF DRWE AIDS ANTI WEB
and does not infect these files. The virus periodically displays a message into left right corner of the screen.
"Firstling 1.0 by Merciful"