diff --git a/README.md b/README.md
new file mode 100644
index 0000000..c1d490e
--- /dev/null
+++ b/README.md
@@ -0,0 +1,35 @@
+# PoC — SAS Desktop DoS via UAC Spoofing
+
+A Windows proof-of-concept that demonstrates how a hidden UAC elevation prompt can be used to block the Secure Attention Sequence (SAS) while a rapid desktop-switching loop prevents the user from regaining control of their session.
+
+> **Disclaimer:** For authorised security research and CTF use only. Do not run against systems you do not own or have explicit written permission to test.
+
+---
+
+## What It Does
+
+1. Creates a shadow desktop invisible to the user and fires a UAC elevation prompt on it. Windows holds the SAS lock for the duration of the pending prompt, meaning Ctrl+Alt+Del and the secure desktop are blocked.
+
+2. Rapidly switches between the shadow desktop and the default desktop at full CPU speed. This thrashes the display pipeline and prevents the system from stabilising — without the UAC lock the user could recover, but with it there is no escape route left to recover into.
+
+3. Installs a system-wide low-level keyboard hook that swallows all input. The only key that passes through is Escape, which tears everything down cleanly.
+
+4. Plays a fullscreen looping video and pins an overlay to the bottom of the screen showing "Press Escape to Quit".
+
+The UAC is the lock. The desktop switching is the hammer. Together they make the session unrecoverable without pressing Escape.
+
+---
+
+## Requirements
+
+- Windows 10 / 11
+- Python 3.x (no third-party packages)
+- Optional: mpv or VLC for the video payload
+
+## Running
+
+```
+python poc_sas_dos.py
+```
+
+Press **Escape** to exit cleanly.