Training 4: Back Up Your Data

Hands-on training · Cybersecurity Basics: Hands-On Training · Training 4 of 8 · About 30 minutes

Backups turn a disaster into an inconvenience. When ransomware, a broken drive or a lost phone strikes, the people with tested backups recover in hours; the people without them can lose everything. In this training you will set up backups using the 3-2-1 rule and prove they work.

Why backups matter

Ransomware encrypts files and often attacks any backups it can reach. In Japan’s October 2026 attacks, backups on the same systems were encrypted too.
Mistakes and failures: deleted files, broken drives and accidents happen to everyone.
Loss and theft: a lost phone should not mean lost photos.

Step 1: Decide what to back up

List the data you cannot afford to lose: documents, photos and videos, work files, tax and financial records, and anything you cannot download again. Apps and the operating system can usually be reinstalled; your own files cannot.

The 3-2-1 rule

The 3-2-1 rule: slide 4 of Training 4, Back Up Your Data

3 copies of your important data: the original plus two backups.
2 different types of storage, for example a cloud service and an external drive.
1 copy offline or off-site, out of reach of ransomware, fire or theft.

Many professionals add “0 errors”: regularly test that backups can actually be restored.

Step 2: Set up automatic backups

Step 2: Set up automatic backups: slide 5 of Training 4, Back Up Your Data

Windows 11: open Windows Backup from the Start menu to back up folders to OneDrive, and use File History (Control Panel › File History) to back up to an external drive.
Mac: connect an external drive and turn on Time Machine in System Settings › General › Time Machine.
iPhone: turn on iCloud Backup in Settings › your name › iCloud › iCloud Backup.
Android: turn on Google One backup in Settings › Google › Backup (names vary by phone maker).

Cloud services have free storage limits; you may need a small paid plan for all your photos and files.

Step 3: Keep one copy offline

Use an external drive dedicated to backups.
Back up regularly, weekly or after important changes.
Disconnect it when the backup finishes.
Store it safely: encrypted (BitLocker To Go on Windows, or the encryption option in Time Machine on a Mac), and kept away from the computer.

Ransomware can encrypt any drive that stays connected. An unplugged drive is out of its reach.

Step 4: Test a restore

Step 4: Test a restore: slide 7 of Training 4, Back Up Your Data

Pick a test file: make a copy of a real document.
Delete the copy from its usual folder.
Restore it from your backup.
Open it and check it is complete.

Repeat this every few months. A backup you have never restored is only a hope.

Your checklist

☐ Listed the files and photos you cannot lose

☐ Automatic cloud backup on for computer and phone

☐ Local backup set up with File History or Time Machine

☐ One copy kept on an unplugged external drive

☐ Backup drive encrypted and stored safely

☐ Restored a test file successfully

☐ Calendar reminder to test again in 3 months

Check your work

What do the numbers in the 3-2-1 rule stand for?
Why should one backup copy be kept offline?
How do you know your backup actually works?

Answers: 1. Three copies, on two types of storage, with one offline or off-site. 2. Because ransomware can encrypt any connected drive, including backups. 3. By regularly restoring a test file and checking it opens correctly.

Coming next: Training 5 · Secure Your Wi-Fi. Router settings, Wi-Fi encryption and guest networks for home and small offices.