Can ransomware encrypted files be recovered?

Short answer

Sometimes. Ransomware encrypts your files in place, so the readable contents are gone from those files until something decrypts them. Free decryptors exist for some ransomware families, agencies advise against paying, and a backup made before the attack is the exit that always works.

A small brass padlock resting closed on a shut blank paper notebook on pale oak wood

Sometimes. It depends on which ransomware family hit you, whether researchers have published a way to break its encryption, and whether you have a backup made before the attack. Ransomware encrypts the files on a device so that the files, and the systems that rely on them, become unusable, and the attacker demands payment in exchange for decryption. After that, the readable contents are gone from those files; what remains is scrambled data that only a decryption key can turn back. There is no universal fix, but free decryptors exist for some families, and a pre-attack backup ends the problem outright.^[1][2]

What encryption did to your files

Ransomware rewrites your files in place. The documents and photos are still on the disk, but their contents have been scrambled so they will not open, and the key that would make them readable belongs to the attacker. No tool can un-delete its way back to the originals, because nothing was deleted: the files themselves were changed. CISA describes the pattern as malware designed to encrypt files on a device, rendering them and the systems that rely on them unusable, followed by a demand for payment in exchange for decryption.^[2]

The first move: check for a free decryptor

Start at the No More Ransom project, which maintains a repository of keys and decryption applications that can unlock data locked by some ransomware types, so victims can recover without paying. Coverage is the catch: the project states that not every type of ransomware has a solution, and asks people to keep checking back as new tools are added. Vendors publish free decryptor collections too, tied to named families; Avast notes some of its tools only work in specific cases, such as files encrypted with an offline key. A tool built for one strain will not decrypt another.^[1][3]

Why paying is not a recovery plan

Paying is a purchase with no guarantee attached. The FBI does not support paying a ransom, because payment does not guarantee a victim regains access to their data, and it reports that some who paid never received decryption keys while others were extorted for more money afterward. The UK NCSC and UK law enforcement do not encourage, endorse or condone paying, and add that a paid-up computer is still infected and that victims who pay are more likely to be targeted again. No agency quotes a success rate for payment, and neither will this page.^[4][5]

Do not keep using the infected machine for anything that matters: the NCSC notes your computer stays infected even if you pay, and files you create or change on it meanwhile can be lost too. Do not pay anyone before getting advice, including whichever service promises guaranteed decryption. The general advice from the No More Ransom project and law enforcement alike is not to pay, and nobody can guarantee recovery.^[1][5]

When a recovery lab is the remaining option

If no decryptor exists for your family and no backup survived, the options narrow, and a specialist recovery lab is what is left. Be realistic about what one can do: any success rate a service advertises for ransomware cases is that service talking about itself, not a figure anyone has checked. Before sending a drive anywhere, ask what the evaluation costs and what you owe if nothing is recovered.^[2][1]

The exit that always works

A backup made before the attack does not depend on the attacker's cooperation or on researchers cracking the encryption, which is why CISA's guidance puts backups first: maintain offline, encrypted backups of data and test them regularly. The NCSC makes the same point about a recent offline backup of your most important files. Order matters. Wipe and rebuild the machine first, because it stays infected until it is cleaned, and restoring files onto a compromised computer just hands them back to the malware. Then restore, and check the files open.^[2][5]

What to do first

If files on your computer are suddenly encrypted

Disconnect the machine from the network: unplug the ethernet cable and turn off Wi-Fi. Ransomware encrypts the files it can reach on a device, and disconnecting stops it reaching anything else.
Identify the family and check for a decryptor. Use the ransom note or an encrypted file to work out which ransomware you have, then check the No More Ransom repository and vendor collections for a matching free tool.
Check your backups. An external drive, cloud account or server copy made before the attack may hold everything that was locked. Look before deciding anything about paying.
Get advice before paying anyone. The FBI does not support paying a ransom, because payment does not guarantee your data comes back, and reporting the infection costs nothing.

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