USB Virus Scan: Protect Your PC

TL;DR

Yes, you can significantly reduce the risk of viruses from USB sticks by scanning them before opening any files or folders. This guide shows you how to do it using Windows Defender and other free tools.

Scanning a USB Stick Before Use

1. Connect Your USB Stick: Plug the USB stick into your computer.
2. Open File Explorer: Press Windows key + E to open File Explorer.
3. Locate the USB Drive: Find your USB drive in the left-hand pane (usually under ‘This PC’ or similar).
4. Right-Click and Scan: Right-click on the USB drive icon. Select “Scan for threats”. Windows Defender will start a scan.
   • If you don’t see ‘Scan for threats’, your antivirus software may handle this automatically. Check its settings.

Using Windows Security (Windows Defender)

Windows Defender is built-in and free, making it a great first line of defence.

1. Open Windows Security: Search for “Windows Security” in the Start menu and open it.
2. Virus & Threat Protection: Click on “Virus & threat protection”.
3. Scan Options: Under ‘Current threats’, click “Scan options”.
4. Choose a Scan Type: Select one of these:
   • Quick scan: Fastest, checks common locations. Good for regular checks.
   • Full scan: Thorough, checks all files and folders. Takes longer.
   • Custom scan: Lets you choose specific folders to scan (select your USB drive here).
5. Start Scan: Click “Scan now”. Windows Defender will report any threats found.

Alternative Free Scanning Tools

If you want a second opinion or prefer another tool, these are good options:

• ClamWin Free Antivirus: A popular open-source antivirus.

  https://www.clamwin.com/

  Download and install it like any other program. Right-click on the USB drive in File Explorer, select ‘Scan with ClamWin’, then follow the prompts.

• Bitdefender Free Edition: A lightweight antivirus scanner.

  https://www.bitdefender.com/free.html

  Download and install it, then run a scan on your USB drive.

Important Considerations

1. Keep Your Antivirus Updated: Regularly update your antivirus software to ensure it can detect the latest threats. Windows Defender updates automatically if enabled.
2. Scan Regularly: Scan USB sticks every time you connect a new one, or before opening files from an old one that hasn’t been scanned recently.
3. Autorun is Disabled (Good!): Modern versions of Windows disable Autorun by default. This prevents viruses from automatically running when you plug in a USB stick. If it’s enabled for some reason, disable it. You can check this via Group Policy Editor (search ‘gpedit.msc’ and navigate to Computer Configuration > Administrative Templates > Windows Components > AutoPlay Policies).
4. Be Careful What You Open: Even after scanning, be cautious about opening files from unknown sources on the USB stick.

Command Line Scanning (Advanced)

For more technical users, you can use the command line to scan a USB drive. This example uses Windows Defender:

mpcmdrun -scan -driveletter E:

Replace E: with the actual drive letter of your USB stick.