Select the volume you would like to scan and click Start. To scan any removable storage devices that are currently connected to your PC, such as external hard drives, USB flash drives, CDs, and DVDs: Click Start next to Removable Volume Scan. Click the “Start Scanning” button to begin the virus scan. Double-click the EXE file to run the Avast tool from the USB drive. Avast Security Pro includes all the malware-crushing moves of its free little brother, along. Need premium Mac antivirus protection? Say hello to Avast Security Pro. Scanning the USB Flash Drive with Avast Antivirus 2017 – USB / DVD Scan Before you start the actual scan, we recommend to adjust its settings a bit, so no virus or malware on the USB is missed. Phishing protection only works well in Chrome and Firefox, but this free utility is still worth a. Avast Security (for Mac) delivers effective malware protection along with unusual bonus features.