February 21, 2016

433MHz OOK Remote

After playing around with my SDR and wireless sockets I had a look at other devices, which also use ASK/OOK modulated signals. I found a different wireless socket system, an alarm system and a sex toy. After analyzing the signals, I wanted do build a remote to control them all. I used an Adafruit Trinket (ATtiny85) as micro controller and a cheap OOK transmitter module at 433MHz. The code on the controller just sends the same signal as the original remote replay attack).

I put some more effort into the alarm system and reversed the full protocol. A packet of the remote simply consists of an identifier and a command (e.g. disarm the system). The alarm system only “listens” to signals with a known identifier. However, there are only 6561 identifiers. Therefore, I implemented a brute-force attack mode, in which my remote sends a disarm command for all identifiers, eventually disabling all alarm systems. This takes about 15 minutes in average.

A brute-force mode was also implemented for both wireless socket systems, allowing to turn on or off any socket within range.

This is what the remote looks like.
OOK-Remote

You can turn on or off any of these devices.
Controllable Devices Controllable Devices

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