Chromebook Gets a USB Guard
Anyone in tech has seen the reports and news about USB sticks with a virus ruining a company network or infecting computers. Google built a small and effective feature: Chromebook Gets a USB Guard.
The USBGuard is a feature that blocks interaction between the mass storage device and the Chrome operating system. The OS will give power to the device, but not let data transmit.
The USBGuard blocks this activity when the Chromebook is in locked mode. When the Chromebook is not in lock mode, the USB will interact as expected as a read/write device.
History of Chrome USBGuard
USBGuard was first introduced as a security enhancement within Chrome OS around 2017, following a growing number of malware incidents spread through USB devices. Prior to this, Chromebooks relied primarily on user vigilance and antivirus scans to prevent malicious payloads delivered via USB flash drives. Google’s security engineers recognized that a locked or unattended Chromebook was particularly vulnerable because simply plugging in a malicious USB device could allow data theft or the installation of malware in seconds.
The concept of USBGuard was inspired by enterprise-level endpoint protection software, which restricts or audits external device connections. By integrating USBGuard natively, Chrome OS offered built-in hardware-level protection, making it much harder for attackers to exploit unattended systems. Over time, USBGuard became a standard feature on managed Chromebooks, especially those deployed in schools, government agencies, and large corporations.
Real-World Use Cases
Schools quickly adopted USBGuard to protect their computer labs and shared Chromebook carts. For example, one U.S. school district reported a significant drop in malware infections after enabling USBGuard. Previously, infected flash drives brought from home were spreading viruses across dozens of student laptops. With USBGuard active, locked Chromebooks ignored all USB data activity until a verified user signed in, eliminating the problem overnight.
Corporations have benefited as well. A financial services company implemented USBGuard on all employee Chromebooks to defend against potential data exfiltration attempts via rogue USB devices. In one incident, a contractor unknowingly carried an infected USB stick. Thanks to USBGuard, the device powered on but did not transmit data, preventing what could have been a major security breach.
This is a good feature to have for any operating system and it’s likely we’ll see something similar come to Mac and Windows computers in the near future.
For those interested in also protecting their USB stick along with their computer, getting a Nexcopy Lock License drive will help. The USB stick is, by default, always in write-protected mode. This means a virus cannot jump onto the drive as writing to the USB is blocked at the hardware level. Only after a password is entered does the drive become read/write. Learn more about the Nexcopy Lock License drive.
