PythonForWindows

PythonForWindows (PFW) is a base of code aimed to make interaction with Windows (on X86/X64) easier (for both 32 and 64 bits Python). Its goal is to offer abstractions around some of the OS features in a (I hope) pythonic way. It also tries to make the barrier between python and native execution thinner in both ways. There is no external dependencies but it relies heavily on the ctypes module.

Let's say that the codebase evolves with my needs, my researches and my curiosity.

Complete online documentation is available here You can find some examples of code in the samples directory or online.

PythonForWindows is principally known for:

• its ALPC-RPC Client (see samples)
• its generated ctypes definitions.

If you have any issue, question or suggestion do not hesitate to create an issue or reach me out. I am always glad to have feedbacks from people using this project.

Installation

PythonForWindows is available on Pypi an this can be installed with

python -m pip install PythonForWindows

You can also install PythonForWindows by cloning it and using the setup.py script:

python setup.py install

Encoding & unicode

PythonForWindows support python2.7 & python3 and is currently tested for Python2.7, 3.6 & 3.11 via Github Workflow

Since 1.0.0, the code uses "wide APIs" whenever possible and accept/returns python3 str (py2.7 unicode type) almost everywhere. Any functions/APIs not accepting unicode string can be considered a bug if its not stated explicitly in the documentation.

Python2

PythonForWindows continues to support python2.7 as its the only way to have it running on Windows XP & Windows Server 2003 which are sadly still seen in production. Encoding errors at print time might be awkward for unicode string on python2, see the PythonForWindows encoding guide in the documentation.

Overview

Processes / Threads

PythonForWindows offers objects around processes and allows you to:

• Retrieve basic process informations (pid, name, ppid, bitness, ...)
• Perform basic interprocess operation (allocation, create thread, read/write memory)
• Explore the PEB (Process Environment Block)
• Execute native and Python code in the context of a process.

I try my best to make those features available for every cross-bitness processes (32 <-> 64 in both ways). This involves relying on non-documented Windows functions/behaviours and also injecting code in the 64bits world of a Syswow64 process. All those operations are also available for the current_process.

You can also make some operation on threads (suspend/resume/wait/get(or set) context/ kill)

>>> import windows
>>> windows.current_process.bitness
32
>>> windows.current_process.token.integrity
SECURITY_MANDATORY_MEDIUM_RID(0x2000)
>>> proc = [p for p in windows.system.processes if p.name == "notepad.exe"][0]
>>> proc
<WinProcess "notepad.exe" pid 16520 at 0x544e410>
>>> proc.bitness
64
>>> proc.peb.modules[:3]
[<RemoteLoadedModule64 "notepad.exe" at 0x3671e90>, <RemoteLoadedModule64 "ntdll.dll" at 0x3671030>, <RemoteLoadedModule64 "kernel32.dll" at 0x3671080>]
>>> k32 = proc.peb.modules[2]
>>> hex(k32.pe.exports["CreateFileW"])
'0x7ffee6761550L'
>>> proc.threads[0]
<WinThread 17688 owner "notepad.exe" at 0x53b47f0>
>>> hex(proc.threads[0].context.Rip)
'0x7ffee68b54b0L'
>>> proc.execute_python("import os")
True
>>> proc.execute_python("exit(os.getpid() + 1)")
# execute_python raise if process died
Traceback (most recent call last):
...
WindowsError: <WinProcess "notepad.exe" pid 16520 (DEAD) at 0x579f610> died during execution of python command
>>> calc
<WinProcess "notepad.exe" pid 16520 (DEAD) at 0x579f610>
>>> calc.exit_code
16521L

System information

Information about the Windows computer running the script are available through the windows.system object.

>>> windows.system
<windows.winobject.system.System object at 0x03FEED10>
>>> windows.system.bitness
64
>>> windows.system.computer_name
'DESKTOP-VKUGISR'
>>> windows.system.product_type
VER_NT_WORKSTATION(0x1)
>>> windows.system.version
(10, 0)
>>> windows.system.version_name
'Windows 10'
>>> windows.system.build_number
'10.0.15063.608'

# windows.system also contains dynamic lists about processes / threads / handles / ...
>>> windows.system.handles[-2:]
[<Handle value=<0x5cc> in process pid=14360>, <Handle value=<0x28e4> in process pid=14360>]
>>> windows.system.processes[:2]
[<WinProcess "[System Process]" pid 0 at 0x433f7d0>, <WinProcess "System" pid 4 at 0x433fd30>]
>>> windows.system.logicaldrives[0]
<LogicalDrive "C:\" (DRIVE_FIXED)>
>>> windows.system.services[23]
<ServiceA "Appinfo" SERVICE_RUNNING(0x4)>

IAT Hook

This codebase is born from my need to have IAT hooks implemented in Python. So the features is present (See online documentation about IAT hooks).

Winproxy

A wrapper around some Windows functions. Arguments name and order are the same, but some have default values and the functions raise exception on call error (I don't like if around all my call).

>>> import windows
>>> help(windows.winproxy.VirtualAlloc)
# Help on function VirtualAlloc in module windows.winproxy:
# VirtualAlloc(lpAddress=0, dwSize=NeededParameter, flAllocationType=MEM_COMMIT(0x1000L), flProtect=PAGE_EXECUTE_READWRITE(0x40L))
#     Errcheck:
#     raise WinproxyError if result is 0

# Positional arguments
>>> windows.winproxy.VirtualAlloc(0, 0x1000)
34537472

# Keyword arguments
>>> windows.winproxy.VirtualAlloc(dwSize=0x1000)
34603008

# NeededParameter must be provided
>>> windows.winproxy.VirtualAlloc()
"""
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "windows\winproxy.py", line 264, in VirtualAlloc
    return VirtualAlloc.ctypes_function(lpAddress, dwSize, flAllocationType, flProtect)
File "windows\winproxy.py", line 130, in perform_call
    raise TypeError("{0}: Missing Mandatory parameter <{1}>".format(self.func_name, param_name))
TypeError: VirtualAlloc: Missing Mandatory parameter <dwSize>
"""

# Error raises exception
>>> windows.winproxy.VirtualAlloc(dwSize=0xffffffff)
"""
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "windows\winproxy.py", line 264, in VirtualAlloc
    return VirtualAlloc.ctypes_function(lpAddress, dwSize, flAllocationType, flProtect)
File "windows\winproxy.py", line 133, in perform_call
    return self._cprototyped(*args)
File "windows\winproxy.py", line 59, in kernel32_error_check
    raise WinproxyError(func_name)
windows.winproxy.error.WinproxyError: VirtualAlloc: [Error 87] The parameter is incorrect.
"""

Native execution

To make the barrier between native and Python code thinner, PythonForWindows allows you to create native function callable from Python (thanks to ctypes) and also embed a simple x86/x64 assembler.

>>> import windows.native_exec.simple_x86 as x86
>>> code = x86.MultipleInstr()
>>> code += x86.Mov("EAX", 41)
>>> code += x86.Inc("EAX")
>>> code += x86.Ret()
>>> code.get_code()
'\xc7\xc0)\x00\x00\x00@\xc3'
# Create a function that takes no parameters and return an uint
>>> f = windows.native_exec.create_function(code.get_code(), [ctypes.c_uint])
>>> f()
42L
# Assemblers can also be used in a more standard way
>>> x86.assemble("cmp edi, 0; jnz :end; mov eax, 1; label :end; ret")
'\x81\xff\x00\x00\x00\x00u\x06\xc7\xc0\x01\x00\x00\x00\xc3'

Token / Security Descriptor

Objects easing access to some information about Token and SecurityDescriptor are also available.

>>> import windows.security
>>> import windows.generated_def as gdef
>>> tok = windows.current_process.token
>>> tok
<Token TokenId=0x6a2b4550 Type=TokenPrimary(0x1)>
>>> tok.username
u'hakril'
>>> tok.type
tagTOKEN_TYPE.TokenPrimary(0x1)
>>> tok.integrity
SECURITY_MANDATORY_MEDIUM_RID(0x2000)
>>> tok.duplicate(type=gdef.TokenImpersonation, impersonation_level=gdef.SecurityIdentification)
<Token TokenId=0x6a3532ce Type=TokenImpersonation(0x2) ImpersonationLevel=SecurityIdentification(0x1)>

# Security Descriptor
>>> sd = windows.security.SecurityDescriptor.from_filename("c:\windows\system32\kernel32.dll")
>>> sd
<SecurityDescriptor object at 0x054E3DF0>
>>> windows.utils.lookup_sid(sd.owner)
(u'NT SERVICE', u'TrustedInstaller')
>>> sd.dacl
<Acl count=6>
>>> list(sd.dacl)
[<AccessAllowedACE mask=2032127>, <AccessAllowedACE mask=1179817>, <AccessAllowedACE mask=1179817>, <AccessAllowedACE mask=1179817>, <AccessAllowedACE mask=1179817>, <AccessAllowedACE mask=1179817>]
>>> sd.dacl[1].sid
<PSID "S-1-5-32-544">

Wintrust

To easily script some signature check script, PythonForWindows implements some wrapper functions around wintrust.dll

>>> import windows.wintrust
>>> windows.wintrust.is_signed(r"C:\Windows\system32\ntdll.dll")
True
>>> windows.wintrust.is_signed(r"C:\Windows\system32\python27.dll")
False
>>> windows.wintrust.full_signature_information(r"C:\Windows\system32\ntdll.dll")
SignatureData(signed=True,
    catalog=u'C:\\Windows\\system32\\CatRoot\\{F750E6C3-38EE-11D1-85E5-00C04FC295EE}\\Package_35_for_KB3128650~31bf3856ad364e35~amd64~~6.3.1.2.cat',
    catalogsigned=True, additionalinfo=0L)
>>> windows.wintrust.full_signature_information(r"C:\Windows\system32\python27.dll")
SignatureData(signed=False, catalog=None, catalogsigned=False, additionalinfo=TRUST_E_NOSIGNATURE(0x800b0100))

WMI

To extract/play with even more information about the system, PythonForWindows is able to perform WMI request.

>>> import windows
>>> windows.system.wmi.select
<bound method WmiNamespace.select of <WmiNamespace "root\cimv2">>
>>> windows.system.wmi.select("Win32_Process")[:3]
[<WmiObject instance of "Win32_Process">, <WmiObject instance of "Win32_Process">, <WmiObject instance of "Win32_Process">]# Get WMI data for current process
>>> windows.system.wmi.select("Win32_Process")[42]["Name"]
u'svchost.exe'
>>> wmi_cp = [p for p in windows.system.wmi.select("Win32_Process") if int(p["Handle"]) == windows.current_process.pid][0]
>>> wmi_cp["CommandLine"], wmi_cp["HandleCount"]
(u'"C:\\Python27\\python.exe"', 227)

Registry

The project also contains some wrapping classes around _winreg for simpler use.

>>> import windows
>>> from windows.generated_def import KEY_WRITE, KEY_READ, REG_QWORD
>>> registry = windows.system.registry
>>> cuuser_software = registry(r'HKEY_CURRENT_USER\Software')
>>> cuuser_software
<PyHKey "HKEY_CURRENT_USER\Software">
>>> cuuser_software.sam
KEY_READ(0x20019)
# Explore subkeys
>>> cuuser_software.subkeys[:3]
[<PyHKey "HKEY_CURRENT_USER\Software\7-Zip">, <PyHKey "HKEY_CURRENT_USER\Software\AppDataLow">, <PyHKey "HKEY_CURRENT_USER\Software\Audacity">]
>>> tstkey = registry('HKEY_CURRENT_USER\TestKey',  KEY_WRITE | KEY_READ)
# Get / Set individual value
>>> tstkey["VALUE"] = 'a_value_for_my_key'
>>> tstkey["VALUE"]
KeyValue(name='VALUE', value=u'a_value_for_my_key', type=1)
>>> tstkey["MYQWORD"] = (123456789987654321, REG_QWORD)  # Default is REG_DWORD for int/long
>>> tstkey["MYQWORD"]
KeyValue(name='MYQWORD', value=123456789987654321L, type=11)
# Explore Values
>>> tstkey.values
[KeyValue(name='MYQWORD', value=123456789987654321L, type=11), KeyValue(name='VALUE', value=u'a_value_for_my_key', type=1)]

Object manager

PythonForWindows uses the native Windows NT API to display some information about the object in the Object Manager's name space. Just like the well-known tools winobj.exe

>>> windows.system.object_manager.root
<KernelObject "\" (type="Directory")>
# The objects of type "Directory" can be acceded just like a dict
>>> list(windows.system.object_manager.root)[:3]
[u'PendingRenameMutex', u'ObjectTypes', u'storqosfltport']
# Find an object by its path
>>> windows.system.object_manager["KnownDLLs\\kernel32.dll"]
<KernelObject "\KnownDLLs\kernel32.dll" (type="Section")>
>>> k32 = windows.system.object_manager["KnownDLLs\\kernel32.dll"]
>>> k32.name, k32.fullname, k32.type
('kernel32.dll', '\\KnownDLLs\\kernel32.dll', u'Section')
# Follow SymbolicLink object
>>> windows.system.object_manager["\\KnownDLLs\\KnownDLLPath"]
<KernelObject "\KnownDLLs\KnownDLLPath" (type="SymbolicLink")>
>>> windows.system.object_manager["\\KnownDLLs\\KnownDLLPath"].target
u'C:\\WINDOWS\\System32'

Scheduled Task

The windows.system.task_scheduler object allows to query and create scheduled task.

This part is still in developpement and the API may evolve

>>> windows.system.task_scheduler
<TaskService at 0x4774670>
>>> windows.system.task_scheduler.root
<TaskFolder "\" at 0x4774710>
>>> task = windows.system.task_scheduler.root.tasks[2]
>>> task
<Task "DemoTask" at 0x47748f0>
>>> task.name
u'DemoTask'
# Explore task actions
>>> task.definition.actions[1]
<ExecAction at 0x4774800>
>>> task.definition.actions[1].path
u'c:\\windows\\python\\python.exe'
>>> task.definition.actions[1].arguments
u'yolo.py --test'

Event logs

The windows.system.event_log object allows to query event logs.

This part is still in developpement and the API may evolve

>>> windows.system.event_log
<windows.winobject.event_log.EvtlogManager object at 0x04A78270>
# Find a channel by its name
>>> chan = windows.system.event_log["Microsoft-Windows-Windows Firewall With Advanced Security/Firewall"]
>>> chan
<EvtChannel "Microsoft-Windows-Windows Firewall With Advanced Security/Firewall">
# Open .evtx files
>>> windows.system.event_log["test.evtx"]
<EvtFile "test.evtx">
# Query a channel for all events
>>> chan.query().all()[:2]
[<EvtEvent id="2004" time="2018-07-12 07:44:08.081504">, <EvtEvent id="2006" time="2018-07-12 07:57:59.806938">]
# Query a channel for some ids
>>> chan.query(ids=2004).all()[:2]
[<EvtEvent id="2004" time="2018-07-12 07:44:08.081504">, <EvtEvent id="2004" time="2018-07-12 07:57:59.815156">]
# Query a channel via XPATH
>>> evt = chan.query("Event/EventData[Data='Netflix']").all()[0]
# Explore event information
>>> evt
<EvtEvent id="2006" time="2018-07-17 10:32:39.160423">
>>> evt.data
{u'ModifyingUser': 69828304, u'RuleName': u'Netflix', u'ModifyingApplication': ...}

ALPC-RPC

ALPC

Classes around Advanced Local Procedure Call (ALPC) syscalls allows to simply write client and server able to send ALPC messages.

>>> import windows.alpc
# Test server juste reply to each message with "REQUEST '{msg_data}' RECEIVED"
>>> client = windows.alpc.AlpcClient(r"\RPC Control\PythonForWindowsTESTPORT")
>>> response = client.send_receive("Hello world !")
>>> response
<windows.alpc.AlpcMessage object at 0x04C0D5D0>
>>> response.data
"REQUEST 'Hello world !' RECEIVED"

Full client/server code for this example is available is the ALPC samples along with a more complex example.

RPC

An RPC-Client based using ALPC communication is also integred

# Server (port ALPC '\RPC Control\HelloRpc') offers:
# Interface '41414141-4242-4343-4444-45464748494a' version 1.0
#   Method 1 -> int Add(int a, int b) -> return a + b
# This Test server is a real RPC Server using rpcrt4.dll and compiled with VS2015.

>>> import windows.rpc
>>> from windows.rpc import ndr
>>> client = windows.rpc.RPCClient(r"\RPC Control\HelloRpc")
>>> client
<windows.rpc.client.RPCClient object at 0x0411E130>
>>> iid = client.bind("41414141-4242-4343-4444-45464748494a")
>>> ndr_params = ndr.make_parameters([ndr.NdrLong] * 2)
# NDR pack + Make RPC call to method 1.
>>> resp = client.call(iid, 1, ndr_params.pack([41414141, 1010101]))
# Unpack the NDR response
>>> result = ndr.NdrLong.unpack(ndr.NdrStream(resp))
>>> result
42424242

A sample with the User Account Control (UAC) and one with lsasrv.dll are available in the RPC samples.

Debugger

PythonForWindows provides a standard debugger to debug other processes.

import windows
import windows.debug
import windows.test
import windows.native_exec.simple_x86 as x86
import windows.generated_def as gdef

from windows.test import pop_proc_32

class MyDebugger(windows.debug.Debugger):
    def on_exception(self, exception):
        code = exception.ExceptionRecord.ExceptionCode
        addr = exception.ExceptionRecord.ExceptionAddress
        print("Got exception {0} at 0x{1:x}".format(code, addr))
        if code == gdef.EXCEPTION_ACCESS_VIOLATION:
            print("Access Violation: kill target process")
            self.current_process.exit()

calc = windows.test.pop_proc_32(dwCreationFlags=gdef.DEBUG_PROCESS)
d = MyDebugger(calc)
calc.execute(x86.assemble("int3; mov [0x42424242], EAX; ret"))
d.loop()

## Ouput ##
Got exception EXCEPTION_BREAKPOINT(0x80000003) at 0x77e13c7d
Got exception EXCEPTION_BREAKPOINT(0x80000003) at 0x230000
Got exception EXCEPTION_ACCESS_VIOLATION(0xc0000005) at 0x230001
Access Violation: kill target process

The debugger handles

• Standard breakpoint int3
• Hardware Execution breakpoint DrX
• Memory breakpoint virtual protect

LocalDebugger

You can also debug your own process (or debug a process by injection) via the LocalDebugger.

The LocalDebugger is an abstraction around Vectored Exception Handler (VEH)

import windows
from windows.generated_def.winstructs import *
import windows.native_exec.simple_x86 as x86

class SingleSteppingDebugger(windows.debug.LocalDebugger):
    SINGLE_STEP_COUNT = 4
    def on_exception(self, exc):
        code = self.get_exception_code()
        context = self.get_exception_context()
        print("EXCEPTION !!!! Got a {0} at 0x{1:x}".format(code, context.pc))
        self.SINGLE_STEP_COUNT -= 1
        if self.SINGLE_STEP_COUNT:
            return self.single_step()
        return EXCEPTION_CONTINUE_EXECUTION

class RewriteBreakpoint(windows.debug.HXBreakpoint):
    def trigger(self, dbg, exc):
        context = dbg.get_exception_context()
        print("GOT AN HXBP at 0x{0:x}".format(context.pc))
        # Rewrite the infinite loop with 2 nop
        windows.current_process.write_memory(self.addr, "\x90\x90")
        # Ask for a single stepping
        return dbg.single_step()


d = SingleSteppingDebugger()
# Infinite loop + nop + ret
code = x86.assemble("label :begin; jmp :begin; nop; ret")
func = windows.native_exec.create_function(code, [PVOID])
print("Code addr = 0x{0:x}".format(func.code_addr))
# Create a thread that will infinite loop
t = windows.current_process.create_thread(func.code_addr, 0)
# Add a breakpoint on the infinite loop
d.add_bp(RewriteBreakpoint(func.code_addr))
t.wait()
print("Done!")

## Output ##

Code addr = 0x6a0002
GOT AN HXBP at 0x6a0002
EXCEPTION !!!! Got a EXCEPTION_SINGLE_STEP(0x80000004) at 0x6a0003
EXCEPTION !!!! Got a EXCEPTION_SINGLE_STEP(0x80000004) at 0x6a0004
EXCEPTION !!!! Got a EXCEPTION_SINGLE_STEP(0x80000004) at 0x6a0005
EXCEPTION !!!! Got a EXCEPTION_SINGLE_STEP(0x80000004) at 0x770c7c04
Done!

The local debugger handles

• Standard breakpoint int3
• Hardware Execution breakpoint DrX

Symbols

Classes around the Symbols APIs of dbghelp.dll are also implemented and can be used independently of the Debugger. The path of dbghelp.dll can also be given via the PFW_DBGHELP_PATH environment variable.

# Python3

>>> from windows.debug import symbols
>>> # symbols.set_dbghelp_path(MY_DBGHELP_PATH)
>>> symbols.engine.options = 0 # Disable defered load
>>> sh = symbols.VirtualSymbolHandler()
>>> ntmod = sh.load_file(r"c:\windows\system32\ntdll.dll", addr=0x420000)
>>> ntmod
<SymbolModule name="ntdll" type=SymPdb pdb="ntdll.pdb" addr=0x420000>
>>> ntmod.name
'ntdll'
>>> ntmod.path
'c:\\windows\\system32\\ntdll.dll'
>>> ntmod.pdb
'c:\\Symbols\\ntdll.pdb\\8D5D5ED5D5B8AA609A82600C14E3004D1\\ntdll.pdb'
>>> sym = sh["ntdll!LdrLoadDll"]
>>> sym
<SymbolInfoW name="LdrLoadDll" start=0x44a160 tag=SymTagFunction>
>>> sym.fullname
'ntdll!LdrLoadDll'
>>> hex(sym.addr)
'0x44a160'
>>> sh.search("ntdll!*CreateFile")
[<SymbolInfoW name="EtwpCreateFile" start=0x47d9ec tag=SymTagFunction>, <SymbolInfoW name="EtwpCreateFile" start=0x47d9ec tag=SymTagPublicSymbol>, <SymbolInfoW name="NtCreateFile" start=0x4c03e0 tag=SymTagPublicSymbol>, <SymbolInfoW name="ZwCreateFile" start=0x4c03e0 tag=SymTagPublicSymbol>, <SymbolInfoW name="__imp_NtCreateFile" start=0x55cb70 tag=SymTagPublicSymbol>]
# Some types exploration
>>> peb = sh.get_type("ntdll!_PEB")
>>> peb
<SymbolType name="_PEB" tag=_SymTagEnum.SymTagUDT(0xb)>
>>> peb.size
2000
>>> peb.children[:3]
[<SymbolType name="InheritedAddressSpace" tag=_SymTagEnum.SymTagData(0x7)>, <SymbolType name="ReadImageFileExecOptions" tag=_SymTagEnum.SymTagData(0x7)>, <SymbolType name="BeingDebugged" tag=_SymTagEnum.SymTagData(0x7)>]
>>> peb.children[2].offset
2

Other stuff (see doc / samples)

• Network
• COM

Acknowledgments

• clmntb for his initial work on windows.security