Scan external media
Scan external media for viruses before use
Before they are read, external storage peripherals (hard disks, USB sticks, optical disks, memory cards etc.) are scanned by antivirus software.
The obligatory scanning of storage peripherals allows the detection of infected media before the host computer can be manipulated. This is a trade-off to avoid eliminating USB ports altogether.
Disable autorun function for external media
The 'auto run' feature triggers, without user intervention, an executable code from an external storage device (optical disk, external hard disk, memory stick, flash card etc.).
This code, which is executed whenever the device is connected, is a major risk of infection for a workstation. It is probably also shared among several users/machines, greatly increasing its harmfulness.