How to Protect Your Files Against Ransomware

Turn on controlled folder access

Windows Security → Virus & threat protection → Ransomware protection → Controlled folder access. This restricts which applications may modify your Documents, Pictures and other protected folders. It is off by default and is the highest-value free setting on a Windows PC.

Keep one backup that ransomware cannot reach

An always-connected external drive gets encrypted along with everything else. You need either a drive you physically unplug, or cloud storage with file version history you can roll back. Test the restore once — an untested backup is a hypothesis.

Close the common entry points

Patch Windows and your browser promptly. Do not enable macros in documents that arrive by email. Disable Remote Desktop unless you need it, and never expose it directly to the internet. Use unique passwords so one breach does not become many.

• •Automatic Windows Update enabled
• •Macros disabled in Office documents from email
• •RDP closed or behind a VPN
• •Unique passwords plus multi-factor authentication
• •One offline or versioned backup

If files are already encrypted

Disconnect the machine immediately to stop the spread. Do not pay before checking whether a free decryptor exists — the No More Ransom project maintains a catalogue for many families. Preserve the ransom note and a few encrypted samples, since decryptors are family-specific. Then rebuild the machine from clean media and restore from backup.