fortra/impacket

Impacket is a Python library used by security researchers and penetration testers (professionals hired to find weaknesses in computer systems) to interact with low-level network protocols. Network protocols are the rules that computers use to communicate, things like how files are shared, how authentication works, and how devices find each other on a network. The library provides detailed, programmable access to a wide range of protocols used mainly in Windows and enterprise networking environments: SMB (the protocol Windows uses for file sharing), Kerberos and NTLM (Windows authentication systems), MSRPC (a system for calling procedures on remote machines), NetBIOS (a legacy network naming system), and partial support for SQL Server (TDS) and directory services (LDAP). In practice, Impacket is used to build security testing tools, for example, simulating attacks like "pass-the-hash" (reusing captured authentication credentials without knowing the actual password), querying remote Windows systems, or inspecting how authentication traffic is structured. It is not designed for production use in commercial products, and the project's stated purpose is research and education. You would use Impacket if you are a security researcher, a penetration tester testing Windows environments, or a developer studying network protocol implementations. It is written in Python and installable via the standard Python package manager (pip or pipx). It is maintained by Fortra's Core Security team.