For how useful USB thumb drives are for quickly toting around and copying files from one computer to another, they can be a bit of a security headache. Programs can be loaded on them with all kinds of malware; they can be obscured in some ways that are difficult to detect, and they can be set up to execute certain programs when they’re plugged in. The general wisdom is to simply avoid untrusted USB devices completely, but that sort of abstinence-only policy rarely works in the real world. If, for some reason, an untrusted USB device absolutely needs to be used, many of these security issues can be mitigated with this tool.
Built by [Novamostra], the device is simple on the surface: it’s a Raspberry Pi Pico mated to a 2-in-1 USB splitter cable. But with the USB Neutralizer software they have written loaded onto the Pico, it automatically destroys the ability of any connected USB thumb drive to load files. The program works by deleting the first and last 34 Logical Block Addressing (LBA) sectors on the drive immediately when it’s plugged in, without doing anything else. This effectively corrupts the drive bad enough to prevent malicious software in the partitions from doing anything, allowing the user to (relatively) safely put the USB drive into their computer and format it for re-use. The code for this tool is also open-source and reviewable on the project’s GitHub page.
Of course, this isn’t a perfect security solution for all USB attacks. It doesn’t erase or replace the firmware on the drive itself, and although firmware-level attacks are rare they’re not out of the question for all users, all the time. It also won’t prevent a malicious physical attack like this high-voltage one, and it may also not stop hidden or obscured partitions or devices programmed for storage and some other nefarious purpose simultaneously, like a USB HID. But still, this solves a great many of the problems associated with getting new drives from semi-untrustworthy sources, like retailers or friends whose computer skills we don’t fully trust.
