The Youfileslock virus falls within the MedusaLocker ransomware family. Ransomware of such sort encrypts all the data on your PC (images, documents, excel tables, audio files, videos, etc) and appends its own extension to every file, leaving the HOW_TO_RECOVER_DATA.html text files in each directory containing encrypted files.
What is Youfileslock virus?
☝️ A strictly correct designation for the Youfileslock would be “a MedusaLocker family ransomware malicious agent”.
Youfileslock adds its extra .youfileslock extension to every file’s name. For instance, a file named “photo.jpg” will be renamed to “photo.jpg.youfileslock”. In the same manner, the Excel sheet with the name “table.xlsx” will end up as “table.xlsx.youfileslock”, and so forth.
In each folder that contains the encrypted files, a HOW_TO_RECOVER_DATA.html text file will appear. It is a ransom money memo. Therein you can find information about the ways of paying the ransom and some other remarks. The ransom note most probably contains a description of how to purchase the decryption tool from the tamperers. That is how they do it.
Youfileslock outline:
| Name | Youfileslock Virus |
| Ransomware family1 | MedusaLocker ransomware |
| Extension | .youfileslock |
| Ransomware note | HOW_TO_RECOVER_DATA.html |
| Detection | Trojan:Win32/RedLineStealer.PS!MTB, Ransom:Win32/Ciluf, MSIL/Agent.VIF |
| Symptoms | Your files (photos, videos, documents) get a .youfileslock extension and you can’t open them. |
| Fix Tool | See If Your System Has Been Affected by Youfileslock virus |
In the picture below, you can see what a directory with files encrypted by the Youfileslock looks like. Each filename has the “.youfileslock” extension added to it.
How did my machine catch Youfileslock ransomware?
There are many possible ways of ransomware injection.
There are currently three most exploited ways for malefactors to have ransomware planted in your system. These are email spam, Trojan infiltration and peer networks.
If you open your inbox and see letters that look just like notifications from utility services companies, postal agencies like FedEx, web-access providers, and whatnot, but whose mailer is unknown to you, beware of opening those letters. They are most likely to have a malicious file attached to them. Therefore, it is even riskier to download any attachments that come with letters like these.
As for the peer-to-peer networks like torrent trackers or eMule, the danger is that they are even more trust-based than the rest of the Web. You can never guess what you download until you get it. So you’d better be using trustworthy resources. Also, it is reasonable to scan the directory containing the downloaded items with the antivirus as soon as the downloading is done.
How do I get rid of the Youfileslock virus?
It is crucial to inform you that besides encrypting your files, the Youfileslock virus will probably deploy the Azorult Spyware on your machine to seize your credentials to various accounts (including cryptocurrency wallets). That spyware3 can extract your credentials from your browser’s auto-filling data.
Often tamperers would unblock several of your files to prove that they really have the decryption program. Since Youfileslock virus is a relatively recent ransomware, anti-malware designers have not yet found a way to undo its work. However, the decoding tools are constantly upgraded, so the solution may soon be available.
Sure thing, if the criminals do the job of encrypting someone’s essential data, the desperate person will probably comply with their demands. Despite that, paying to criminals gives no guarantee that you’re getting your data back. It is still dangerous. After receiving the money, the racketeers may send a wrong decryption key to the victim. There were reports about criminals simply vanishing after getting the ransom without even bothering to reply.
The best countermeasure to ransomware is to have aan OS restore point or the copies of your critical files in the cloud drive or at least on an external disk. Obviously, that might be not enough. Your most crucial thing could be that file you were working on when it all started. But at least it is something. It is also advisable to scan your PC for viruses with the antivirus program after the OS restoration.
Youfileslock is not the only ransomware of its kind, since there are other specimens of ransomware out there that act in the same manner. For instance, Hkgt, Lltt, Llqq, and some others. The two major differences between them and the Youfileslock are the ransom amount and the method of encryption. The rest is almost identical: documents become encoded, their extensions altered, ransom notes emerge in each folder containing encrypted files.
Some lucky users were able to decrypt the blocked files with the aid of the free tools provided by anti-ransomware developers. Sometimes the racketeers accidentally send the decryption key to the victims in the ransom readme. Such an extraordinary fail allows the victim to restore the files. But naturally, one should never expect such a chance. Make no mistake, ransomware is a criminals’ technology to pull the money out of their victims.
How to avoid ransomware infiltration?
Youfileslock ransomware has no superpower, so as any similar malware.
You can armour your system from ransomware infiltration taking several easy steps:
- Never open any emails from unknown senders with unknown addresses, or with content that has nothing to do with something you are expecting (can you win in a money prize draw without even taking part in it?). In case the email subject is likely something you are waiting for, check all elements of the suspicious email with caution. A hoax letter will always contain mistakes.
- Do not use cracked or untrusted software. Trojan viruses are often shared as a part of cracked products, possibly as a “patch” preventing the license check. Understandably, potentially dangerous programs are difficult to tell from reliable software, as trojans sometimes have the functionality you seek. You can try searching for information on this program on the anti-malware forums, but the best way is not to use such software.
Reasons why I would recommend GridinSoft4
Download Removal Tool.
Run the setup file.
Press “Install” button.
Once installed, Anti-Malware will automatically run.
Wait for the Anti-Malware scan to complete.
Click on “Clean Now”.
Frequently Asked Questions
🤔 How can I open “.youfileslock” files?Are the “.youfileslock” files accessible?
Unfortunately, no. You need to decipher the “.youfileslock” files first. Then you will be able to open them.
🤔 The encrypted files are very important to me. How can I decrypt them quickly?
It’s good if you have fаr-sightedly saved copies of these important files elsewhere. In case you haven’t, there is still a chance that you do have a Restore Point from some time ago to roll back the whole system to the moment when it had no virus yet, but already had your files. There are other ways to beat ransomware, but they take time.
🤔 What actions should I take if the Youfileslock ransomware has blocked my PC and I can’t get the activation key.
🤔 What could help the situation right now?
Many of the blocked files might still be within your reach
- If you sent or received your important files by email, you could still download them from your online mailbox.
- You may have shared images or videos with your friends or family members. Simply ask them to send those pictures back to you.
- If you have initially downloaded any of your files from the Web, you can try to do it again.
- Your messengers, social networks pages, and cloud storage might have all those files too.
- Maybe you still have the needed files on your old PC, a notebook, mobile, flash memory, etc.
USEFUL TIP: You can employ file recovery programs6 to retrieve your lost information since ransomware encrypts the copies of your files, deleting the original ones. In the video below, you can learn how to use PhotoRec for such a restoration, but be advised: you can do it only after you remove the ransomware itself with an anti-malware program.
Also, you can contact the following official fraud and scam sites to report this attack:
- In the United States: On Guard Online;
- In Canada: Canadian Anti-Fraud Centre;
- In the United Kingdom: Action Fraud;
- In Australia: SCAMwatch;
- In New Zealand: Consumer Affairs Scams;
- In France: Agence nationale de la sécurité des systèmes d’information;
- In Germany: Bundesamt für Sicherheit in der Informationstechnik;
- In Ireland: An Garda Síochána;
To report the attack, you can contact local executive boards. For instance, if you live in USA, you can have a talk with FBI Local field office, IC3 or Secret Service.

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