An anonymous reader writes from a report via Softpedia: An attacker can use a modified USB Ethernet adapter to fool Windows and Mac computers into giving away their login credentials. The attack relies on using a modified USB Ethernet adapter that runs special software, which tricks the attacked computer into accepting the Ethernet adapter as the network gateway, DNS, and WPAD server. The attack is possible because most computers will automatically install any plug-and-play (PnP) USB device. Even worse, when installing the new (rogue) USB Ethernet adapter, the computer will give out the local credentials needed to install the device. The custom software installed on the USB intercepts these credentials and logs them to an SQLite database. This attack can take around 13 seconds to carry out, and the USB Ethernet adapter can be equipped with an LED that tells the attacker when the login credentials have been stolen.