CIRCLean - USB key sanitizer

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This project targets anyone receiving a USB key from an untrusted source and who wants to see the content without having to open the original and potentially malicious files.

The code runs on a Raspberry Pi, which also means it is not required to plug or open the original USB key on a computer.

CIRCLean does not require any technical prerequisites of any kind and can be used by anyone.


Step 1

Unplug the device:

Step 2

Plug the untrusted key in the top usb slot of the Raspberry Pi:

Step 3

Plug your own key in the bottom usb slot:

Note: Make sure your own key is bigger than the untrusted one. The extracted documents might be bigger than the original ones.

Step 4

Connect the power to the micro USB:

Step 5

If you have a Raspberry Pi with a diode, wait until the blinking stops:

Else, plug a headset and listen to some music during the conversion. When the music stops, the conversion is finished.

Step 6

Unplug the device and remove the USB keys:

Hot to get your own instance

The source code with all the sources to convert the content and the scripts needed to build your own image to write on a SD card are available.

If you prefer to use a pre-build image (last update: 2013-12-09), you can use CIRCLean (2013-12-09).

Please make sure you received the right file by checking the hash:

  • MD5: d31b73b85a26854085889a854aa51239
  • SHA1: e13082c921506c96552af7d867a26aebd9b3fdd5
  • SHA256: ffc04d53b4f9abb02f4ee6578976c651b4741ffac0520eb32c377c2e00036bec

Technical details

The sanitizing is done by converting and copying the content of the untrusted key to the trusted one. It is based on the mime type of the files, you can have more details in the file of the git repository. Also, a short description of all the scripts is available in the same file.