NetRipper is a post exploitation tool targeting Windows systems which uses API hooking in order to intercept network traffic and encryption related functions from a low privileged user, being able to capture both plain-text traffic and encrypted traffic before encryption/after decryption.
NetRipper was released at Defcon 23, Las Vegas, Nevada.
Usage of NetRipper for attacking targets without prior mutual consent is illegal. It is the end user’s responsability to obey all applicable local, state and federal laws. Developers assume no liability and are not responsible for any misuse or damage caused by this program!
The post-exploitation activities in a penetration test can be challenging if the tester has low-privileges on a fully patched, well configured Windows machine. This work presents a technique for helping the tester to find useful information by sniffing network traffic of the applications on the compromised machine, despite his low-privileged rights. Furthermore, the encrypted traffic is also captured before being sent to the encryption layer, thus all traffic (clear-text and encrypted) can be sniffed. The implementation of this technique is a tool called NetRipper which uses API hooking to do the actions mentioned above and which has been especially designed to be used in penetration tests, but the concept can also be used to monitor network traffic of employees or to analyze a malicious application.
NetRipper should be able to capture network traffic from: Putty, WinSCP, SQL Server Management Studio, Lync (Skype for Business), Microsoft Outlook, Google Chrome, Mozilla Firefox. The list is not limited to these applications but other tools may require special support.
NetRipper.exe - Configures and inject the DLL DLL.dll - Injected DLL, hook APIs and save data to files netripper.rb - Metasploit post-exploitation module
Injection: NetRipper.exe DLLpath.dll processname.exe Example: NetRipper.exe DLL.dll firefox.exe Generate DLL: -h, --help Print this help message -w, --write Full path for the DLL to write the configuration data -l, --location Full path where to save data files (default TEMP) Plugins: -p, --plaintext Capture only plain-text data. E.g. true -d, --datalimit Limit capture size per request. E.g. 4096 -s, --stringfinder Find specific strings. E.g. user,pass,config Example: NetRipper.exe -w DLL.dll -l TEMP -p true -d 4096 -s user,pass
msf exploit(multi/handler) > use post/windows/gather/netripper/netripper msf post(windows/gather/netripper/netripper) > show options Module options (post/windows/gather/netripper/netripper): Name Current Setting Required Description ---- --------------- -------- ----------- DATALIMIT 65535 no The number of bytes to save from requests/responses DATAPATH TEMP no Where to save files. E.g. C:\Windows\Temp or TEMP DLLPATH no Where to find NetRipper DLLs. Default is /usr/share/metasploit-framework... PLAINTEXT false no True to save only plain-text data PROCESSIDS no Process IDs. E.g. 1244,1256 PROCESSNAMES no Process names. E.g. firefox.exe,chrome.exe SESSION yes The session to run this module on. STRINGFINDER DEFAULT no Search for specific strings in captured data
Set PROCESSNAMES or PROCESSIDS and run.
- mkdir /usr/share/metasploit-framework/modules/post/windows/gather/netripper
- cp Metasploit/netripper.rb /usr/share/metasploit-framework/modules/post/windows/gather/netripper/netripper.rb
- cp x86/DLL.x86.dll /usr/share/metasploit-framework/modules/post/windows/gather/netripper/DLL.x86.dll
- cp x64/DLL.x64.dll /usr/share/metasploit-framework/modules/post/windows/gather/netripper/DLL.x64.dll
- mkdir /opt/metasploit-framework/modules/post/windows/gather/netripper
- cp Metasploit/netripper.rb /opt/metasploit-framework/modules/post/windows/gather/netripper/netripper.rb
- cp x86/DLL.x86.dll /opt/metasploit-framework/modules/post/windows/gather/netripper/DLL.x86.dll
- cp x64/DLL.x64.dll /opt/metasploit-framework/modules/post/windows/gather/netripper/DLL.x64.dll
@HarmJ0y Added Invoke-NetRipper.ps1 PowerShell implementation of NetRipper.exe
Please note that the PowerShell module is not up to date.
- PlainText – Allows to capture only plain-text data
- DataLimit – Save only first bytes of requests and responses
- StringFinder – Find specific string in network traffic
You can find the changelog in the “Changelog.md” file and compilation instructions in the “Compilation.md” file.
- Reflective DLL Injection (https://github.com/stephenfewer/ReflectiveDLLInjection) from Stephen Fewer
- minhook library (https://github.com/TsudaKageyu/minhook) from Tsuda Kageyu.
Ionut Popescu (@NytroRST)