USB Flash Drive for Industrial Control Systems

Why hardware write-protected USB drives are critical for Industrial Control Systems.

Honeywell’s recent cybersecurity report noted that 37% of threats are designed to spread via removable media, nearly doubling from 19% in 2020. That spike highlights how USB flash drives remain a weak link in Industrial Control Systems (ICS) if not properly managed.

Honeywell’s solution, Honeywell Forge, is software that monitors connected devices and flags risks [Ref:1]. Monitoring is useful, but it doesn’t prevent malware from getting in. Prevention requires the right kind of media in the first place.

Air-gapped systems and the USB problem

ICS environments are typically air-gapped—they’ve never touched the internet. Updates happen through portable storage, usually a USB flash drive. If that drive is compromised, malware bypasses all other defenses and lands directly in the control system. The only effective safeguard is a drive that is physically incapable of being infected while in transit.

Software tricks—like setting a read-only attribute with DISKPART or flipping registry rights—don’t cut it. Those methods are easy to reverse and offer little real protection against a determined attacker.

A hardware-level solution

The Lock License flash drive by Nexcopy takes a different approach. Its write protection is enforced at the hardware controller level. Unlike software locks, hardware-level controls cannot be undone with a few registry edits. This makes the device far more resistant to tampering or malware injection.

The Lock License design also balances usability. A content creator can temporarily unlock the drive with a password to write new data. Once disconnected, the drive automatically returns to its secure state: read-only. That means you can safely prepare update media in a trusted environment, then deploy it to an ICS without fear of the drive being altered along the way.

Final thought

It’s hard not to ask: why weren’t USB drives built like this from the beginning? For ICS, where uptime and safety are everything, a hardware write-protected flash drive isn’t just a convenience—it’s a necessity.