Int 21 Fn 4A  - Virus???                                                   [v]

   AH = 4Ah
   BX = 00B6h
   ES = CX

Return: ???

Note:  this call is intercepted by the Search&Destroy SDRes v27.03 bundled
     with Novell DOS 7, and is presumably some virus's installation check

See Also: AH=0Eh/DL=ADh,AH=4Ah/BX=FFFFh,AH=D2h"VIRUS"