What Is Ransomware and How to Keep It from Locking Your Files
Ransomware encrypts your files and demands money to release them — yet a handful of habits, led by disconnected backups, cut the risk to almost nothing.
Ransomware is one of the most damaging kinds of cyberattack out there: it locks up your files and demands money to "release" them. The good news is that a few simple measures cut the risk to almost zero.
The plain-language explanation
Ransomware is a malicious program that encrypts (locks with a key you do not have) every file on your computer, then displays a message demanding payment — usually in cryptocurrency — to supposedly restore your access. It typically arrives through emails with malicious attachments or programs downloaded from untrustworthy sites.
Worth knowing: paying the ransom does NOT guarantee you get your files back, and it funds the attackers to keep targeting more people. Security experts advise never paying.
How to prevent it: the measures that actually work
1. Keep backups — and don't leave them permanently connected
This is the single most effective protection. If your files also live on a disconnected external drive or in the cloud, a ransomware attack stops being a catastrophe: you simply restore your files and move on.
2. Be suspicious of unexpected email attachments
Especially .zip or .exe files, or Office
documents asking you to "enable macros" that you were not expecting —
even if they appear to come from someone you know.
3. Keep Windows and your programs up to date
Many ransomware attacks exploit security flaws that are already known and fixed in newer software versions.
4. Use an antivirus with real-time protection enabled
Windows Defender already includes "Controlled folder access", a feature built specifically against ransomware: turn it on under Windows Security → Virus & threat protection → Ransomware protection settings.
Tip: follow the 3-2-1 backup rule: at least 3 copies of your files, on 2 different types of storage, with 1 of them kept away from home (in the cloud, for example).
Warning: if you have already been hit, do not immediately power off the machine or pay the ransom — disconnect it from the network (cable or Wi-Fi) so the infection cannot spread to other devices, and seek professional help.
Common mistakes
Relying solely on an antivirus with no backups is the costliest mistake. No antivirus catches 100% of new threats; backups are the only thing that guarantees you recover your files no matter what.
Frequently asked questions
Should I pay if a ransom is demanded for my files?
Security experts advise never paying: there is no guarantee of recovering the files, and payment funds future attacks. The best defence is having backups so you never depend on that decision.
Does ransomware affect cloud files too?
It can affect synced folders (such as OneDrive or Google Drive) if the encryption happens before you notice the attack, since changes get synchronised. That is why you should also keep a copy that is not constantly auto-syncing.
Can phones get ransomware too?
Yes, although it is less common than on computers. It usually arrives through apps installed outside the official stores (Google Play or the App Store).