The Olsavelock virus belongs to the ransomware type of infection. This sample belongs to MedusaLocker ransomware family. Malware of such sort encrypts all the data on your computer (photos, text files, excel sheets, music, videos, etc) and appends its own extension to every file, creating the How_to_back_files.html files in every directory containing encrypted files.
What is known about the Olsavelockvirus?
☝️ A scientifically accurate designation for the Olsavelock would be “a ransomware infection”.
Olsavelock adds its extra .olsavelock31 extension to every file’s title. The number on the end may vary from one attack to another. For example, a file entitled “photo.jpg” will be turned into “photo.jpg.olsavelock31” or “photo.jpg.olsavelock14”. Just like the Excel file with the name “table.xlsx” will be renamed to “table.xlsx.olsavelock31”, and so on.
In every directory containing the encoded files, a How_to_back_files.html text file will appear. It is a ransom money note. It contains information on the ways of contacting the racketeers and some other information. The ransom note usually contains a description of how to buy the decryption tool from the tamperers. That is how they do it.
Olsavelock overview:
| Name | Olsavelock Virus |
| Family | MedusaLocker |
| Extension | .olsavelock31; number on the end may differ |
| Ransomware note | How_to_back_files.html |
| Detection | Trojan:Win32/Bomitag.D!rfn, Trojan-Ransom.Win32.Rector.im, BAT/KillBackup.C |
| Symptoms | Your files (photos, videos, documents) have a .olsavelock31 extension and you can’t open them. |
| Fix Tool | See If Your System Has Been Affected by Olsavelock virus |
In the picture below, you can see what a folder with files encrypted by the Olsavelock looks like. Each filename has the “.olsavelock31” extension appended to it.
How did my computer get infected with Olsavelock ransomware?
There is a huge number of possible ways of ransomware injection.
Nowadays, there are three most popular methods for hackers to have ransomware settled in your digital environment. These are email spam, Trojan injection and peer-to-peer networks.
If you open your inbox and see emails that look like familiar notifications from utility services companies, postal agencies like FedEx, web-access providers, and whatnot, but whose addresser is unknown to you, be wary of opening those emails. They are most likely to have a malware item enclosed in them. So it is even more dangerous to open any attachments that come with emails like these.
Another option for ransom hunters is a Trojan file model. A Trojan is an object that gets into your machine pretending to be something legal. For example, you download an installer for some program you want or an update for some service. But what is unboxed reveals itself a harmful agent that encrypts your data. As the update wizard can have any title and any icon, you’d better be sure that you can trust the resource of the things you’re downloading. The best way is to use the software companies’ official websites.
As for the peer file transfer protocols like torrents or eMule, the danger is that they are even more trust-based than the rest of the Web. You can never know what you download until you get it. So you’d better be using trustworthy websites. Also, it is reasonable to scan the folder containing the downloaded objects with the anti-malware utility as soon as the downloading is complete.
How do I get rid of the Olsavelock virus?
It is important to note that besides encrypting your files, the Olsavelock virus will most likely deploy Vidar Stealer on your computer to seize your credentials to different accounts (including cryptocurrency wallets). That program can extract your logins and passwords from your browser’s auto-filling data.
Sometimes tamperers would decode few of your files to prove that they really have the decryption tool. Since Olsavelock virus is a relatively recent ransomware, safety measures engineers have not yet found a method to undo its work. However, the anti-ransomware tools are frequently updated, so the effective countermeasure may soon arrive.
Of course, if the tamperers do the job of encoding victim’s critical files, the hopeless person will most likely fulfill their demands. Nevertheless, paying to racketeers does not necessarily mean that you’re getting your files back. It is still dangerous. After receiving the ransom, the racketeers may send a wrong decryption code to the victim. There were reports about racketeers simply disappearing after getting the money without even bothering to reply.
The optimal safety measure against ransomware is to have a system restore point or the copies of your essential files in the cloud storage or at least on an external disk. Of course, that might be not enough. Your most crucial thing could be that file you were working upon when it all happened. Nevertheless, it is something. It is also wise to scan your drives with the anti-malware utility after the system is rolled back.
Olsavelock is not the only ransomware of its kind, since there are other specimens of ransomware out there that act in the same manner. Examples of those are Coty, Foza, Coza, and some others. The two main differences between them and the Olsavelock are the ransom amount and the encoding method. The rest is almost identical: files become encoded, their extensions altered, ransom notes are found in each directory containing encoded files.
Some fortunate victims were able to decode the blocked files with the help of the free software provided by anti-ransomware specialists. Sometimes the criminals mistakenly send the decryption code to the victims in the ransom readme. Such an epic fail allows the user to restore the files. But naturally, one should never rely on such a chance. Remember, ransomware is a bandits’ tool to pull the money out of their victims.
How to avoid ransomware infection?
Olsavelock ransomware has no endless power, so as any similar malware.
You can armour yourself from ransomware injection taking several easy steps:
- Never open any letters 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 more or less something you are expecting, scrutinize all elements of the suspicious email with caution. A hoax email will surely contain mistakes.
- Never use cracked or unknown software. Trojans are often shared as an element of cracked products, most likely as a “patch” which prevents the license check. But dubious programs are very hard to tell from reliable software, because trojans sometimes have the functionality you need. You can try searching for information about this software product on the anti-malware forums, but the optimal way is not to use such programs at all.
Reasons why I would recommend GridinSoft1
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 “.olsavelock31” files?Is it possible to open“.olsavelock31” files?
Negative. That is why ransomware is so frustrating. Until you decode the “.olsavelock31” files you will not be able to access them.
🤔 I really need to decrypt those “.olsavelock31” files ASAP. How can I do that?
Hopefully, you have made a copy of those important files. 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. The rest of the methods require patience.
🤔 What should I do if the Olsavelock virus has blocked my computer and I can’t get the activation code.
🤔 What could help the situation right now?
Some of the encrypted files can be found elsewhere.
- If you exchanged your important files via email, you could still download them from your online mailbox.
- You might have shared photographs or videos with your friends or family members. Simply ask them to send those pictures back to you.
- If you have initially got any of your files from the Web, you can try doing it again.
- Your messengers, social media pages, and cloud drives might have all those files as well.
- It might be that you still have the needed files on your old computer, a laptop, phone, memory stick, etc.
USEFUL TIP: You can use file recovery programs3 to get your lost data back since ransomware encrypts the copies of your files, deleting the authentic ones. In the video below, you can see how to recover your files with PhotoRec, but remember: you can do it only after you kill the virus with an antivirus 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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