VBA RunPE
Description
A simple yet effective implementation of the RunPE technique in VBA. This code can be used to run executables from the memory of Word or Excel. It is compatible with both 32 bits and 64 bits versions of Microsoft Office 2010 and above.
Usage 1 - PE file on disk
- In the
Exploit
procedure at the end of the code, set the path of the file you want to execute.
strSrcFile = "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe"
/!\ If you're using a 32 bits version of Microsoft Office on a 64 bits OS, you must specify 32 bits binaries.
strSrcFile = "C:\Windows\SysWOW64\cmd.exe"
strSrcFile = "C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe"
- Specify the command line arguments (optional).
strArguments = "-exec Bypass"
This will be used to form a command line equivalent to:
C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -exec Bypass
- (Optional) Enable View > Immediate Window (
Ctrl+G
) to check execution and error logs. - Run the
Exploit
macro!
Usage 2 - Embedded PE
- Use
pe2vba.py
to convert a PE file to VBA. This way, it can be directly embedded into the macro.
user@host:~$ python pe2vba.py meterpreter.exe
[+] Created file 'meterpreter.exe.vba'.
- Replace the following code in
RunPE.vba
with the the content of the.vba
file which was generated in the previous step.
' ================================================================================
' ~~~ EMBEDDED PE ~~~
' ================================================================================
' CODE GENRATED BY PE2VBA
Private Function PE() As String
Dim strPE As String
strPE = ""
PE = strPE
End Function
- (Optional) Enable View > Immediate Window (
Ctrl+G
) to check execution and error logs. - Run the
Exploit
macro!
/!\ When using an embedded PE, the macro will automatically switch to this mode because the PE()
method will return a non-empty string.
Credits
This code is mainly a VBA adaptation of the C++ implementation published by @Zer0Mem0ry (32 bits only). https://github.com/Zer0Mem0ry/RunPE
The PE embedding method was inspired by @DidierStevens' work. https://blog.didierstevens.com/
Misc
Tests
This code was tested on the following platforms:
- Windows 7 Pro 32 bits + Office 2010 32 bits
- Windows 7 Pro 64 bits + Office 2016 32 bits
- Windows 2008 R2 64 bits + Office 2010 64 bits
- Windows 10 Pro 64 bits + Office 2016 64 bits
Currently, this doesn't work with all Windows binaries. For example, it can't be used to run regedit.exe. I guess I need to do some manual imports of missing DLLs.
Side notes
Here is a table of correspondence between some Win32 and VBA types:
C++ | VBA | Arch |
---|---|---|
BYTE | Byte | 32 & 64 |
WORD | Integer | 32 & 64 |
DWORD, ULONG, LONG | Long | 32 & 64 |
DWORD64 | LongLong | 64 |
HANDLE | LongPtr(*) | 32 & 64 |
LPSTR | String | 32 & 64 |
LPBYTE | LongPtr(*) | 32 & 64 |
(*) LongPtr is a "dynamic" type, it is 4 Bytes long in Office 32 bits and 8 Bytes long in Office 64 bits. https://msdn.microsoft.com/fr-fr/library/office/ee691831(v=office.14).aspx
What about older versions of Microsoft Office (<=2007)?
As mentionned in the description, this code only works with Office 2010 and above. The reason for this is that the LongPtr
type is extensively used. It was first introduced in Office 2010 to help developers make architecture independant code. Indeed, as described above, its size will be automatically adapted depending on the architecture of the Office process (32-bits / 64-bits).
So, if you try to run this code in Office 2007, you will get a User-defined type not defined
error message for each variable using the LongPtr
type. To work around this issue, you can replace all the LongPtr
occurences with Long
(32-bits) or LongLong
(64-bits). Use Ctrl+H
in your favorite text editor! ;)
Note: the code could be updated to take this compatibility issue into account but it would require too much effort for relatively little gain.