TL;DR
Importing metadata (data *about* your files – author, date created, location etc.) can introduce cyber security risks and cause IT problems. This guide explains the dangers and how to protect yourself.
Understanding the Risks
Metadata isn’t usually what you see when you open a file, but it’s often embedded within it. Bad actors can hide malicious code or sensitive information in metadata. Here are some common risks:
- Malware: Metadata can be used to deliver viruses and other nasty software.
- Data Leaks: Personal or confidential data might be hidden in file properties, exposing it unexpectedly. Think location data from photos, author names on documents etc.
- File Corruption: Incorrectly formatted metadata can make files unusable.
- System Instability: Processing large amounts of flawed metadata can slow down or crash your computer.
How to Mitigate Metadata Import Risks
Here’s a step-by-step guide to reduce the chances of problems:
1. Source Verification
- Know Your Sources: Only import metadata from trusted sources you are confident about. Avoid downloading files from unknown websites or accepting them from untrusted senders.
- Check File Extensions: Be wary of unexpected file extensions. A document claiming to be a .docx but with an unusual extension (.exe, .scr) is a red flag.
2. Scanning for Malware
- Antivirus Scan: Before importing *any* metadata, scan the file(s) with up-to-date antivirus software. This is your first line of defence.
- Dedicated Malware Scanners: Consider using a second opinion scanner (like VirusTotal – https://www.virustotal.com) for extra assurance. Upload the file to check against multiple engines.
3. Metadata Inspection
Before using imported metadata, examine it carefully.
- File Properties: Right-click on the file and select ‘Properties’ (Windows) or ‘Get Info’ (macOS). Review all tabs for suspicious entries.
- Metadata Viewers/Editors: Use dedicated tools to view and edit metadata. Examples include ExifTool (command line – powerful but requires learning), or graphical tools like Metadata2Go (https://metadata2go.com).
- Command Line Example (ExifTool): To view the metadata of an image file:
exiftool filename.jpg
4. Metadata Sanitisation
Remove unnecessary or potentially harmful metadata.
- Strip Metadata: Use tools to remove all metadata from files before using them. This is a drastic but effective measure if you don’t need the data.
- Windows: Right-click on file(s), select ‘Properties’, go to the ‘Details’ tab, and click ‘Remove Properties and Personal Information’.
- macOS: Use a tool like MAT2 (Metadata Anonymisation Toolkit) or command line tools.
- Edit Metadata Manually: Carefully edit metadata to remove sensitive information, correct errors, and ensure consistency.
5. System Protection
- Keep Software Updated: Regularly update your operating system, antivirus software, and other applications. Updates often include cyber security patches.
- User Account Control (UAC): Ensure UAC is enabled on Windows to prevent unauthorized changes to your system.
- Backups: Regularly back up your important files so you can restore them if something goes wrong.
6. Virtualisation/Sandboxing
For high-risk metadata imports, consider using a virtual machine or sandbox environment.
- Virtual Machine: Run the import process within a separate virtual operating system to isolate it from your main system.
- Sandbox: Use a sandboxing tool (like Windows Sandbox) to create an isolated testing environment.

