LLMNR/NBT-NS/mDNS Poisoner and NTLMv1/2 Relay.
Responder is an LLMNR, NBT-NS and MDNS poisoner. It will answer to specific NBT-NS (NetBIOS Name Service) queries based on their name suffix (see: http://support.microsoft.com/kb/163409). By default, the tool will only answer to File Server Service request, which is for SMB.
The concept behind this is to target our answers, and be stealthier on the network. This also helps to ensure that we don't break legitimate NBT-NS behavior. You can set the -r option via command line if you want to answer to the Workstation Service request name suffix. The option -d is also available if you want to poison Domain Service name queries.
- Built-in SMB Auth server.
Supports NTLMv1, NTLMv2 hashes with Extended Security NTLMSSP by default. Successfully tested from Windows 95 to Server 2022, Samba and Mac OSX Lion. Clear text password is supported for NT4, and LM hashing downgrade when the --lm option is set. If --disable-ess is set, extended session security will be disabled for NTLMv1 authentication. SMBv2 has also been implemented and is supported by default.
- Built-in MSSQL Auth server.
In order to redirect SQL Authentication to this tool, you will need to set the option -r (NBT-NS queries for SQL Server lookup are using the Workstation Service name suffix) for systems older than windows Vista (LLMNR will be used for Vista and higher). This server supports NTLMv1, LMv2 hashes. This functionality was successfully tested on Windows SQL Server 2005, 2008, 2012, 2019.
- Built-in HTTP Auth server.
In order to redirect HTTP Authentication to this tool, you will need to set the option -r for Windows version older than Vista (NBT-NS queries for HTTP server lookup are sent using the Workstation Service name suffix). For Vista and higher, LLMNR will be used. This server supports NTLMv1, NTLMv2 hashes and Basic Authentication. This server was successfully tested on IE 6 to IE 11, Edge, Firefox, Chrome, Safari.
Note: This module also works for WebDav NTLM authentication issued from Windows WebDav clients (WebClient). You can now send your custom files to a victim.
- Built-in HTTPS Auth server.
Same as above. The folder certs/ contains 2 default keys, including a dummy private key. This is intentional, the purpose is to have Responder working out of the box. A script was added in case you need to generate your own self signed key pair.
- Built-in LDAP Auth server.
In order to redirect LDAP Authentication to this tool, you will need to set the option -r for Windows version older than Vista (NBT-NS queries for LDAP server lookup are sent using the Workstation Service name suffix). For Vista and higher, LLMNR will be used. This server supports NTLMSSP hashes and Simple Authentication (clear text authentication). This server was successfully tested on Windows Support tool "ldp" and LdapAdmin.
- Built-in DCE-RPC Auth server.
In order to redirect DCE-RPC Authentication to this tool, you will need to set the option -r and -d (NBT-NS queries for DCE-RPC server lookup are sent using the Workstation and Domain Service name suffix). For Vista and higher, LLMNR will be used. This server supports NTLMSSP hashes. This server was successfully tested on Windows XP to Server 2019.
- Built-in FTP, POP3, IMAP, SMTP Auth servers.
This modules will collect clear text credentials.
- Built-in DNS server.
This server will answer type SRV and A queries. This is really handy when it's combined with ARP spoofing.
- Built-in WPAD Proxy Server.
This module will capture all HTTP requests from anyone launching Internet Explorer on the network if they have "Auto-detect settings" enabled. This module is highly effective. You can configure your custom PAC script in Responder.conf and inject HTML into the server's responses. See Responder.conf.
- Browser Listener
This module allows to find the PDC in stealth mode.
When the option -f is used, Responder will fingerprint every host who issued an LLMNR/NBT-NS query. All capture modules still work while in fingerprint mode.
For MITM on Windows XP/2003 and earlier Domain members. This attack combined with the DNS module is pretty effective.
DHCP Inform Spoofing. Allows you to let the real DHCP Server issue IP addresses, and then send a DHCP Inform answer to set your IP address as a primary DNS server, and your own WPAD URL. To inject a DNS server, domain, route on all Windows version and any linux box, use -R
- Analyze mode.
This module allows you to see NBT-NS, BROWSER, LLMNR, DNS requests on the network without poisoning any responses. Also, you can map domains, MSSQL servers, workstations passively, see if ICMP Redirects attacks are plausible on your subnet.
All hashes are printed to stdout and dumped in a unique John Jumbo compliant file, using this format:
Log files are located in the "logs/" folder. Hashes will be logged and printed only once per user per hash type, unless you are using the Verbose mode (-v).
- Responder will log all its activity to Responder-Session.log
- Analyze mode will be logged to Analyze-Session.log
- Poisoning will be logged to Poisoners-Session.log
Additionally, all captured hashed are logged into an SQLite database which you can configure in Responder.conf
This tool listens on several ports: UDP 137, UDP 138, UDP 53, UDP/TCP 389,TCP 1433, UDP 1434, TCP 80, TCP 135, TCP 139, TCP 445, TCP 21, TCP 3141,TCP 25, TCP 110, TCP 587, TCP 3128, Multicast UDP 5355 and 5353.
If you run Samba on your system, stop smbd and nmbd and all other services listening on these ports.
For Ubuntu users:
Edit this file /etc/NetworkManager/NetworkManager.conf and comment the line:
dns=dnsmasq. Then kill dnsmasq with this command (as root):
killall dnsmasq -9
Any rogue server can be turned off in Responder.conf.
This tool is not meant to work on Windows.
For OSX, please note: Responder must be launched with an IP address for the -i flag (e.g. -i YOUR_IP_ADDR). There is no native support in OSX for custom interface binding. Using -i en1 will not work. Also to run Responder with the best experience, run the following as root:
launchctl unload /System/Library/LaunchDaemons/com.apple.Kerberos.kdc.plist
launchctl unload /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist
launchctl unload /System/Library/LaunchDaemons/com.apple.smbd.plist
launchctl unload /System/Library/LaunchDaemons/com.apple.netbiosd.plist
First of all, please take a look at Responder.conf and tweak it for your needs.
Running the tool:
Typical Usage Example:
./Responder.py -I eth0 -rPv
--version show program's version number and exit. -h, --help show this help message and exit. -A, --analyze Analyze mode. This option allows you to see NBT-NS, BROWSER, LLMNR requests without responding. -I eth0, --interface=eth0 Network interface to use. -i 10.0.0.21, --ip=10.0.0.21 Local IP to use (only for OSX) -e 10.0.0.22, --externalip=10.0.0.22 Poison all requests with another IP address than Responder's one. -b, --basic Return a Basic HTTP authentication. Default: NTLM -r, --wredir Enable answers for netbios wredir suffix queries. Answering to wredir will likely break stuff on the network. Default: Off -d, --NBTNSdomain Enable answers for netbios domain suffix queries. Answering to domain suffixes will likely break stuff on the network. Default: Off -f, --fingerprint This option allows you to fingerprint a host that issued an NBT-NS or LLMNR query. -w, --wpad Start the WPAD rogue proxy server. Default value is Off -u UPSTREAM_PROXY, --upstream-proxy=UPSTREAM_PROXY Upstream HTTP proxy used by the rogue WPAD Proxy for outgoing requests (format: host:port) -F, --ForceWpadAuth Force NTLM/Basic authentication on wpad.dat file retrieval. This may cause a login prompt. Default: Off -P, --ProxyAuth Force NTLM (transparently)/Basic (prompt) authentication for the proxy. WPAD doesn't need to be ON. This option is highly effective when combined with -r. Default: Off --lm Force LM hashing downgrade for Windows XP/2003 and earlier. Default: Off --disable-ess Force ESS downgrade. Default: Off -v, --verbose Increase verbosity.
You can contribute to this project by donating to the following $XLM (Stellar Lumens) address:
Or BTC address:
Late Responder development has been possible because of the donations received from individuals and companies.
We would like to thanks those major sponsors:
Black Hills Information Security: http://www.blackhillsinfosec.com/
Red Siege Information Security: https://www.redsiege.com/
And all, ALL the pentesters around the world who donated to this project.
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Responder, a network take-over set of tools created and maintained by Laurent Gaffie.
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.