Collection of DLL function export forwards for DLL export function proxying.
Typical usecase is for backdooring applications for persistence purposes. E.g:
- inspect the target application you wish to backdoor with procmon, see which DLLs it loads via the static IAT. You can clearly see this as the application tries to load Windows DLLs first from the applications own folder before attempting to load them from System32/SysWOW64.
- pick one, a common target is
C:\Windows\System32\version.dll
- fire up Visual Studio, generate a new DLL project
- add the code from here https://github.com/magnusstubman/dll-exports/blob/main/win10.19042/System32/version.dll.cpp
- add your own maliciousness e.g. malware, e.g. as I did in https://dumpco.re/blog/alternative-to-lsass-dumping
- compile - remember to compile for correct architecture
- copy your newly compiled DLL to the target application's home directory
- restart application and see it load your code, while preserving functionality
generator.py
generates a list of DLLs in the target folders and use pefile
to generate a list of exported functions for each, that are written to individual files containing relevant linker directives. E.g. for C:\Windows\System32\version.dll:
https://github.com/magnusstubman/dll-exports/blob/main/win10.19044/System32/version.dll.cpp
#pragma comment(linker, "/export:GetFileVersionInfoA=\"C:\\Windows\\System32\\version.GetFileVersionInfoA\"")
#pragma comment(linker, "/export:GetFileVersionInfoByHandle=\"C:\\Windows\\System32\\version.GetFileVersionInfoByHandle\"")
#pragma comment(linker, "/export:GetFileVersionInfoExA=\"C:\\Windows\\System32\\version.GetFileVersionInfoExA\"")
#pragma comment(linker, "/export:GetFileVersionInfoExW=\"C:\\Windows\\System32\\version.GetFileVersionInfoExW\"")
#pragma comment(linker, "/export:GetFileVersionInfoSizeA=\"C:\\Windows\\System32\\version.GetFileVersionInfoSizeA\"")
#pragma comment(linker, "/export:GetFileVersionInfoSizeExA=\"C:\\Windows\\System32\\version.GetFileVersionInfoSizeExA\"")
#pragma comment(linker, "/export:GetFileVersionInfoSizeExW=\"C:\\Windows\\System32\\version.GetFileVersionInfoSizeExW\"")
#pragma comment(linker, "/export:GetFileVersionInfoSizeW=\"C:\\Windows\\System32\\version.GetFileVersionInfoSizeW\"")
#pragma comment(linker, "/export:GetFileVersionInfoW=\"C:\\Windows\\System32\\version.GetFileVersionInfoW\"")
#pragma comment(linker, "/export:VerFindFileA=\"C:\\Windows\\System32\\version.VerFindFileA\"")
#pragma comment(linker, "/export:VerFindFileW=\"C:\\Windows\\System32\\version.VerFindFileW\"")
#pragma comment(linker, "/export:VerInstallFileA=\"C:\\Windows\\System32\\version.VerInstallFileA\"")
#pragma comment(linker, "/export:VerInstallFileW=\"C:\\Windows\\System32\\version.VerInstallFileW\"")
#pragma comment(linker, "/export:VerLanguageNameA=\"C:\\Windows\\System32\\version.VerLanguageNameA\"")
#pragma comment(linker, "/export:VerLanguageNameW=\"C:\\Windows\\System32\\version.VerLanguageNameW\"")
#pragma comment(linker, "/export:VerQueryValueA=\"C:\\Windows\\System32\\version.VerQueryValueA\"")
#pragma comment(linker, "/export:VerQueryValueW=\"C:\\Windows\\System32\\version.VerQueryValueW\"")
Are DEF files yout thing? https://github.com/magnusstubman/dll-exports/blob/main/win10.19044/System32/version.dll.def
EXPORTS
GetFileVersionInfoA="C:\Windows\System32\version".GetFileVersionInfoA
GetFileVersionInfoByHandle="C:\Windows\System32\version".GetFileVersionInfoByHandle
GetFileVersionInfoExA="C:\Windows\System32\version".GetFileVersionInfoExA
GetFileVersionInfoExW="C:\Windows\System32\version".GetFileVersionInfoExW
GetFileVersionInfoSizeA="C:\Windows\System32\version".GetFileVersionInfoSizeA
GetFileVersionInfoSizeExA="C:\Windows\System32\version".GetFileVersionInfoSizeExA
GetFileVersionInfoSizeExW="C:\Windows\System32\version".GetFileVersionInfoSizeExW
GetFileVersionInfoSizeW="C:\Windows\System32\version".GetFileVersionInfoSizeW
GetFileVersionInfoW="C:\Windows\System32\version".GetFileVersionInfoW
VerFindFileA="C:\Windows\System32\version".VerFindFileA
VerFindFileW="C:\Windows\System32\version".VerFindFileW
VerInstallFileA="C:\Windows\System32\version".VerInstallFileA
VerInstallFileW="C:\Windows\System32\version".VerInstallFileW
VerLanguageNameA="C:\Windows\System32\version".VerLanguageNameA
VerLanguageNameW="C:\Windows\System32\version".VerLanguageNameW
VerQueryValueA="C:\Windows\System32\version".VerQueryValueA
VerQueryValueW="C:\Windows\System32\version".VerQueryValueW
I havn't taken KnownDLLs
into account.
Keep in mind that the DLLs listed in HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\KnownDLLs
and any DLL that they load is also considered to be a known DLL, thus the standard search order does not apply.
exports.py
is a small util script for showing what exports a given DLL has:
$ ./exports.py version.dll
binary: version.dll
image base: 0x0000000180000000 (6442450944)
architecture: 64-bit
+----------------------------+--------------------------------+------------------+-----------+
| name | address (imagebase + relative) | relative address | ordinal |
+----------------------------+--------------------------------+------------------+-----------+
| GetFileVersionInfoA | 0x00000001800010f0 | 0x000010f0 | 1 (0x1) |
| GetFileVersionInfoByHandle | 0x0000000180002370 | 0x00002370 | 2 (0x2) |
| GetFileVersionInfoExA | 0x0000000180001e90 | 0x00001e90 | 3 (0x3) |
| GetFileVersionInfoExW | 0x0000000180001070 | 0x00001070 | 4 (0x4) |
| GetFileVersionInfoSizeA | 0x0000000180001010 | 0x00001010 | 5 (0x5) |
| GetFileVersionInfoSizeExA | 0x0000000180001eb0 | 0x00001eb0 | 6 (0x6) |
| GetFileVersionInfoSizeExW | 0x0000000180001090 | 0x00001090 | 7 (0x7) |
| GetFileVersionInfoSizeW | 0x00000001800010b0 | 0x000010b0 | 8 (0x8) |
| GetFileVersionInfoW | 0x00000001800010d0 | 0x000010d0 | 9 (0x9) |
| VerFindFileA | 0x0000000180001ed0 | 0x00001ed0 | 10 (0xa) |
| VerFindFileW | 0x0000000180002560 | 0x00002560 | 11 (0xb) |
| VerInstallFileA | 0x0000000180001ef0 | 0x00001ef0 | 12 (0xc) |
| VerInstallFileW | 0x0000000180003320 | 0x00003320 | 13 (0xd) |
| VerLanguageNameA | KERNEL32.VerLanguageNameA | 0x00004e6c | 14 (0xe) |
| VerLanguageNameW | KERNEL32.VerLanguageNameW | 0x00004e97 | 15 (0xf) |
| VerQueryValueA | 0x0000000180001030 | 0x00001030 | 16 (0x10) |
| VerQueryValueW | 0x0000000180001050 | 0x00001050 | 17 (0x11) |
+----------------------------+--------------------------------+------------------+-----------+