Portable storage includes CDs, DVDs, memory sticks or external hard-drives. When using these devices:
Never connect or insert a storage device into your computer or open files if you are unsure of its origin or owner, or if your anti-virus software is not up-to-date.
Scan your device before opening any files using your anti-virus software.
If you are sending files to someone else, save the file to the portable device, then scan the device using your anti-virus software before giving it to them.