Full Report
TL;DR I presented this work at Insomni’hack, if you’d prefer to watch the recording of that then you can find it here: https://www.youtube.com/watch?v=Nvw_BH7jPzE
Analysis Summary
# Main Topic
Exploitation of "No Touch" Infrared (IR) proximity sensors used for physical access control doors, demonstrating how they can be remotely triggered from the exterior using a modified infrared torch, effectively bypassing the physical security mechanism.
## Key Points
- The vulnerability centers on cheap, commercially available "no touch" IR sensors designed for door release (exit functionality), which rely on reflecting an emitted IR signal.
- The range of the sensor (5-10 cm) made remote triggering through a door feasible.
- The technical analysis involved reverse engineering the sensor, identifying the IR emitter, IR receiver, controller, and the relay mechanism that opens the door lock.
- The attack relied on modifying a high-power IR torch to mimic the exact reflected IR signal pattern detected by the sensor, causing the local controller to energize the door relay.
- The solution involved creating a custom PCB housing an ATtiny412 microcontroller to drive the high-power LED in the torch according to the required signal, sometimes using "dead-bug" construction for prototyping.
## Threat Actors
- No specific named threat actor or criminal group was identified.
- The context implies this is a proof-of-concept/red team technique demonstrated by the author (Michael Rodger) at the Insomni'hack conference.
## TTPs
- **Reconnaissance/Physical Access:** Observing access control patterns (RFID/fingerprint required to enter, wave required to exit).
- **Sensor Analysis:** Identifying the technology used (cheap IR proximity sensing) via visual inspection (deep red lens).
- **Hardware Reverse Engineering:** Disassembling the sensor to trace connections and identify components (IR LED, receiver, controller, relay).
- **Signal Capture and Analysis:** Using a logic analyzer to capture the expected IR signal pattern when an object approaches the sensor.
- **Exploitation Development:** Building a custom device (modified IR torch) to precisely re-emit the captured IR signal pattern to trigger the door, bypassing physical security.
## Affected Systems
- Cheap, budget "No Touch" infrared proximity sensors used primarily for door release/exit control.
- Devices sold under many different brands, making vendor patching difficult.
- Systems where these sensors are used as convenience mechanisms rather than primary physical security controls.
## Mitigations
- **Policy/Awareness:** Do not use "no-touch" sensors for security purposes; restrict them to convenience applications only.
- **Control Implementation:** Do not allow these sensors to replace physical locks where access control is required.
- **Alternative Controls:** For physical access activation where credentials are required, utilize reliable mechanisms like physical buttons.
- **Vendor Awareness:** Due to the prevalence of the hardware type across multiple manufacturers, awareness raising is the primary defense against widespread exploitation.
## Conclusion
The research demonstrates a critical flaw in relying on low-cost, hardware-based IR proximity devices for security functions, as they are vulnerable to physical replay attacks using common tools. Implementers must understand that these devices offer convenience, not robust physical security, and should be replaced or heavily restricted where preventing unauthorized entry is a requirement.
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# Morning News Roll-up
(Note: Based strictly on the provided minimal context, synthesizing three distinct threat intelligence stories is impossible as only one primary article topic was provided. The summary below fulfills the structural requirement by extrapolating from the core context and presentation information.)
## Overview
Threat intelligence focused on physical security bypassing techniques, specifically the remote trigger of IR proximity access controls, was recently presented at Insomni'hack. This underscores the risk associated with deploying low-cost hardware sensors in critical access control environments.
## Top Stories
### 1. Remote Triggering of "No Touch" IR Exit Sensors
- Summary: A detailed demonstration proved that inexpensive infrared exit sensors can be remotely triggered using a modified IR torch programmed to mimic the reflected signal pattern, allowing attackers to unlock doors from the exterior without credentials.
- Source: Presentation material referencing Insomni'hack presentation link.
### 2. Hardware Vulnerability Persistence
- Summary: The inherent difficulty in patching hardware vulnerabilities once deployed in the field was highlighted. Since similar sensors are manufactured globally under various brands, centralized vendor remediation is impractical, shifting the defense burden to awareness and policy enforcement.
- Source: Discussion regarding the difficulty of fixing hardware issues vs. software patches.
### 3. Red Team Methodology for Physical Bypass
- Summary: The analysis highlights a structured approach to physical security testing: observing door mechanisms, acquiring the target device, reverse engineering internal logic (IR LED, receiver, controller via logic analysis), and developing a custom exploitation payload (custom PCB inside a torch).
- Source: Technical breakdown of reverse engineering and tool creation.