Kali Linux

Nosferatu : Lsass NTLM Authentication Backdoor

Nosferatu is a Lsass NTLM Authentication Backdoor

How It Works

First, the DLL is injected into the lsass.exe process, and will begin hooking authentication WinAPI calls. The targeted function is MsvpPasswordValidate(), located in NtlmShared.dll. In the pursuit of not being detected, the hooked function will call the original function and allow for the normal flow of authentication. Only after seeing that authentication has failed will the hook swap out the actual NTLM hash with the backdoor hash for comparison.

Usage

Nosferatu must be compiled as a 64 bit DLL. It must be injected using the a DLL Injector with SeDebugPrivilege.

You can see it loaded using Procexp:

Login example using Impacket:

R K

Recent Posts

How OpenClaw Works

Imagine if you had a super-powered assistant who could automatically handle all the boring, repetitive…

1 week ago

How to Use the Linux find Command to Locate Files Like a Pro

Managing files efficiently is a core skill for anyone working in Linux, whether you're a…

1 week ago

How to Check Open Ports in Linux Using netstat, ss, and lsof

Open ports act as communication endpoints between your Linux system and the outside world. Every…

1 week ago

Best Endpoint Monitoring Tools for 2026

Introduction In today’s cyber threat landscape, protecting endpoints such as computers, smartphones, and tablets from…

2 weeks ago

Best 9 Incident Response Automation Tools

Introduction In today's fast-paced cybersecurity landscape, incident response is critical to protecting businesses from cyberattacks.…

2 weeks ago

How AI Puts Data Security at Risk

Artificial Intelligence (AI) is changing how industries operate, automating processes, and driving new innovations. However,…

3 months ago