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/* modified (from http://securityxploded.com/memory-execution-of-executable.php) */
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "loader.h"
#define DEREF_32( name )*(DWORD *)(name)
static volatile PVOID kernel32 asm("__kernel32") = NULL;
static volatile PVOID getproc asm("__getproc") = NULL;
static volatile DWORD EntryAddr asm("__EntryAddr");
static volatile PVOID memalloc asm("__memalloc") = NULL;
static volatile PVOID ldr_ptr asm("__ldr") = NULL;
static volatile struct loader_x86_data ldr;
static volatile DWORD size = 0x0;
static volatile PVOID vpointer = NULL;
static volatile DWORD retval asm("__retval") = -1;
int main(int argc, char *argv[])
{
if (argc != 2 && argc != 3 && argc != 4) {
fprintf(stderr, "usage: %s path-to-dynamic-library [preferred-Virtual-Address] [wait-time]\n", argv[0]);
return -1;
}
DWORD dwWait = 2;
if (argc == 4) {
errno = 0;
dwWait = strtoul(argv[3], NULL, 10);
if (errno != 0)
dwWait = 2;
}
BOOL doAllocAt = FALSE;
PVOID allocPtr = NULL;
if (argc >= 3) {
doAllocAt = TRUE;
char* errch = NULL;
allocPtr = (PVOID)strtoul(argv[2], &errch, 16);
}
HANDLE handle;
HINSTANCE laddress;
LPSTR libname;
DWORD byteread;
PIMAGE_NT_HEADERS nt;
PIMAGE_SECTION_HEADER section;
DWORD dwValueA;
DWORD dwValueB;
DWORD dwValueC;
DWORD dwValueD;
// read the file
printf("Reading file..\n");
handle = CreateFile(argv[1],GENERIC_READ,0,0,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0);
if (handle == INVALID_HANDLE_VALUE) {
fprintf(stderr, "%s: file(%s) does not exist or is not readable\n", argv[0], argv[1]);
return -1;
}
// get the file size
size = GetFileSize(handle,NULL);
if (size <= 0) {
fprintf(stderr, "%s: invalid file(%s) size\n", argv[0], argv[1]);
return -1;
}
// Allocate the space
vpointer = VirtualAlloc(NULL,size,MEM_COMMIT,PAGE_READWRITE);
// read file on the allocated space
ReadFile(handle,vpointer,size,&byteread,NULL);
CloseHandle(handle);
printf("File loaded into memory ..\n");
printf("address............: 0x%X (%lu)\n", (unsigned int)vpointer, (long unsigned int)vpointer);
printf("size...............: 0x%X (%lu)\n", (unsigned int)size, size);
printf("Parse PE-Header ..\n");
// read NT header of the file
nt = (PIMAGE_NT_HEADERS)((PCHAR)vpointer + ((PIMAGE_DOS_HEADER)vpointer)->e_lfanew);
printf("e_lfanew...........: 0x%X (%ld)\n", (unsigned int)((PIMAGE_DOS_HEADER)vpointer)->e_lfanew, ((PIMAGE_DOS_HEADER)vpointer)->e_lfanew);
handle = GetCurrentProcess();
// get VA of entry point
printf("AddressOfEntryPoint: 0x%X (%ld)\n", (unsigned int)nt->OptionalHeader.AddressOfEntryPoint, nt->OptionalHeader.AddressOfEntryPoint);
printf("ImageBase..........: 0x%X (%ld)\n", (unsigned int)nt->OptionalHeader.ImageBase, nt->OptionalHeader.ImageBase);
printf("SizeOfImage........: 0x%X (%ld)\n", (unsigned int)nt->OptionalHeader.SizeOfImage, nt->OptionalHeader.SizeOfImage);
printf("SizeOfHeaders......: 0x%X (%ld)\n", (unsigned int)nt->OptionalHeader.SizeOfHeaders, nt->OptionalHeader.SizeOfHeaders);
printf("SizeOptionalHeader.: 0x%X (%d)\n", (unsigned int)nt->FileHeader.SizeOfOptionalHeader, nt->FileHeader.SizeOfOptionalHeader);
// Allocate the space with Imagebase as a desired address allocation request
memalloc = VirtualAllocEx(
handle,
(doAllocAt == FALSE ? (LPVOID)nt->OptionalHeader.ImageBase : allocPtr),
nt->OptionalHeader.SizeOfImage,
MEM_RESERVE | MEM_COMMIT,
PAGE_EXECUTE_READWRITE
);
// Check for NULL (esp. if the user wants to chooose a specific VA)
if (!memalloc) {
printf("FATAL: VirtualAllocEx failed with %d\n", (int)GetLastError());
exit(1);
}
EntryAddr = (DWORD)memalloc + nt->OptionalHeader.AddressOfEntryPoint;
// Write headers on the allocated space
WriteProcessMemory(handle,
memalloc,
vpointer,
nt->OptionalHeader.SizeOfHeaders,
0
);
// write sections on the allocated space
section = IMAGE_FIRST_SECTION(nt);
printf("sizeof(section)....: 0x%X (%u)\n", sizeof(IMAGE_SECTION_HEADER), sizeof(IMAGE_SECTION_HEADER));
printf("FirstSectionRVA....: 0x%X (%ld)\n", (unsigned int)section[0].VirtualAddress, section[0].VirtualAddress);
printf("FirstSectionPTR....: 0x%X (%ld)\n", (unsigned int)section[0].PointerToRawData, section[0].PointerToRawData);
if ((unsigned int)memalloc != (unsigned int)nt->OptionalHeader.ImageBase) {
printf("Allocated memory block does not start at DLL image base!\n"
" -> 0x%X != 0x%X\n", (unsigned int)memalloc, (unsigned int)nt->OptionalHeader.ImageBase);
}
for (ULONG i = 0; i < nt->FileHeader.NumberOfSections; i++)
{
WriteProcessMemory(
handle,
(PCHAR)memalloc + section[i].VirtualAddress,
(PCHAR)vpointer + section[i].PointerToRawData,
section[i].SizeOfRawData,
0
);
}
if (*(DWORD*)&(nt->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT]) != 0x00000000)
{
// read import dirctory, if exists
dwValueB = (DWORD) &(nt->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT]);
// get the VA
dwValueC = (DWORD)(memalloc) +
((PIMAGE_DATA_DIRECTORY)dwValueB)->VirtualAddress;
while(((PIMAGE_IMPORT_DESCRIPTOR)dwValueC)->Name)
{
// get DLL name
libname = (LPSTR)((DWORD)(memalloc) +
((PIMAGE_IMPORT_DESCRIPTOR)dwValueC)->Name);
// Load dll
laddress = LoadLibrary(libname);
// get first thunk, it will become our IAT
dwValueA = (DWORD)(memalloc) +
((PIMAGE_IMPORT_DESCRIPTOR)dwValueC)->FirstThunk;
// resolve function addresses
while(DEREF_32(dwValueA))
{
dwValueD = (DWORD)(memalloc) + DEREF_32(dwValueA);
// get function name
LPSTR Fname = (LPSTR)((PIMAGE_IMPORT_BY_NAME)dwValueD)->Name;
// get function addresses
DEREF_32(dwValueA) = (DWORD)GetProcAddress(laddress,Fname);
dwValueA += 4;
}
dwValueC += sizeof( IMAGE_IMPORT_DESCRIPTOR );
}
} else printf("No Import Table found, nothing to import ..\n");
memset((void*)&ldr, '\0', sizeof(ldr));
ldr.ptrToDLL = (uint32_t)vpointer;
ldr.sizOfDLL = size;
unsigned char marker[] = { _LOADER_ENDMARKER };
memcpy((void*)&ldr.endMarker, &marker[0], sizeof(ldr.endMarker));
ldr_ptr = (volatile PVOID) &ldr;
kernel32 = LoadLibraryA("KERNEL32.dll");
getproc = GetProcAddress((void*)kernel32, "GetProcAddress");
printf("Calling DLL AdrOfEntry ..\n");
// call the entry point :: here we assume that everything is ok.
asm volatile(
".intel_syntax noprefix\n"
"pushad\n\t"
"pushfd\n\t"
"mov ebx,0xdeadbeef\n\t"
"mov ecx,[__getproc]\n\t"
"mov edx,[__kernel32]\n\t"
"mov edi,__memalloc\n\t"
"mov esi,__ldr\n\t"
"push 0x00000000\n\t"
"call [__EntryAddr]\n\t"
"pop esi\n\t"
"mov [__retval],eax\n\t"
"popfd\n\t"
"popad\n\t"
".att_syntax\n"
);
sleep(dwWait);
printf("DLL returned: %X (%d)\n", (unsigned int)retval, (int)retval);
printf("GetLastError: 0x%X (%ld)\n", (unsigned int)GetLastError(), GetLastError());
return retval;
}
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