37% of threats specifically designed to utilize removable media almost doubled from 19% in the 2020 report. 79% of cyber threats originating from USB devices or removable media could lead to a critical business disruption in the operational technology (OT) environment. At the same time, there was a 30% increase in the use of USB devices in production facilities last year, highlighting the growing dependence on removable media. Intruders are using removable media and USB devices as an initial attack vector to penetrate networks.
Source: https://www.helpnetsecurity.com/2021/06/28/usb-threats-business-impact/