Remove .Osiris Virus (Locky Ransomware) -

Remove .Osiris Virus (Locky Ransomware)

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This article will help you remove .osiris file extension virus (Locky ransomware) successfully. Follow the ransomware removal instructions below carefully.

Another version of the top 3 malware ever to be recorded, Locky Ransomware has come out into the open in a massive spam campaign infecting users as of now. The ransom malware aims to encrypt the files on the users’ computers after which changes their names and adds the .osiris file extension to the files. The algorithms used by the ransomware virus are RSA-2048 and AES-128 and they make sure the files become no longer openable until the victim of the virus pays the ransom of 3 BTC to restore the files, which is not guaranteed. Continue reading this article in order to familiarize yourself with the latest Locky iteration and learn what is the best way to eliminate it permanently from your computer.

Threat Summary

NameLocky .osiris
TypeRansomware, Cryptovirus
Short DescriptionThe .osiris virus encrypts your data and then displays a ransom message with instructions for payment.
SymptomsEncrypted files by .osiris Locky will have the .osiris expansion after their name and their names changed with random characters appended to them.
Distribution MethodSpam Emails, Email Attachments, malicious .xls files, .htm Files, .js files, .ZIP archives
Detection Tool See If Your System Has Been Affected by Locky .osiris


Malware Removal Tool

User ExperienceJoin Our Forum to Discuss Locky .osiris.
Data Recovery ToolWindows Data Recovery by Stellar Phoenix Notice! This product scans your drive sectors to recover lost files and it may not recover 100% of the encrypted files, but only few of them, depending on the situation and whether or not you have reformatted your drive.

.osiris Locky Virus – What Is New

The clever individuals who have coded Locky ransomware have become stuck to a method which is very well-known to work best, even though a little outdated – spam e-mails. The crooks have a wide network of resources to spread the malware and the e-mail messages they use are very cleverly designed fake messages. This tactic is also known as “social engineering” or simply playing the inexperienced user for access to his PC.

What the cyber-criminals behind Locky do is they attack couple of documents among which is a malicious .xls file pretending to be Microsoft excel which may conduct the infection by Locky ransomware using a malicious macro. Accompanying the .xls file are several .txt files just to make the e-mail seem more legitimate. The body of the e-mail discovered by TMMalAnalyst (Twitter) states the following message:


Another e-mail was discovered later and uploaded in Pastebin with those contents:

Dear {name},
Our accountants have noticed a mistake in the payment bill #DEC-12112015.
The full information regarding the mistake, and further recommendations are in the attached document.
Please confirm the amount and let us know if you have any questions.
Attachment: -> -W24C24SS543.js

And accompanying this message are the malicious files attached which once clicked on by the user make the successful infection with Locky .osiris inevitable. This is done with the assistance of an extremely large network of distribution hosts:

.osiris Locky - Distribution Locations

Are the Botnet Rumors True?

Several rumors surfaced that Locky ransomware has been using the ransomware infection just as an excuse to cause a second infection with an information-stealing botnet malware. For those uninformed, botnet is malware that replicates automatically on a given network hence increasing the impact and it’s “zombie network” of submissive computers to the cyber-criminal controlling it.

So far, Tripwire has reported this event to occur in the .zzzzz iteration of Locky ransomware (previous one to .osiris) and many feel convinced that history shall repeat itself, primarily because not much has changed between the two iterations of the ransomware. So what is expected from this iteration is to repeat the same process – after infecting the victim to connect to an external IP address and make the computer a part of a large-scale bot network. This is extremely dangerous because someone in control may damage or take advantage of a vast number of machines, and even simultaneously damage them in some cases.

How Does The .osiris Locky Virus Work

After the user has been infected via this malicious infection file, whether it is .htm, .js or .xls, the ransomware is already activated on the computer and slips past any real-time defenses and process monitoring services of standard security software.

Then Locky .osiris ransomware may modify the registry sub-key Desktop so that it changes the wallpaper of the infected computer to the default Locky wallpaper:


After this, the .osiris ransomware drops the following files on the infected system:

  • OSIRIS-{RANDOM}.htm in %Documents%
  • Shtefans1.spe in %Temp%
  • Rundll32.exe (malicious executable file pretending to be legitimate rundll process of Windows)

After these files are dropped, the Locky .osiris virus begins the encryption procedure. To successfully encrypt the files on the infected computer, the ransomware virus uses a strong mixture of RSA (Rivest-Shamir-Adleman) and AES(Advanced Encryption Standard) which are ciphers that were confirmed to be used by the government to encode secret files for defensive purposes. These ciphers replace blocks or segments of data on the source code of the encrypted file and this makes it no longer openable. After the .osiris virus encrypts the files, it also respectively ads it’s distinctive extension and random A-Z, 0-9 identification on each encrypted file. The files are reported by Marcelo Rivero (Twitter) to be altered in the following format:


After the user becomes presented with the .hta file which has instructions on how to pay funds, the user is led to a website, advertising Locky Decrypter, just like it’s previous .shit, .zzzzz, .aesir, .odin, .locky and .thor ransomware variants:


Should the user choose to pay the ransom amount, there is no guarantee on whether or not his files will be successfully recovered or not. This is why malware research experts strongly advise against trusting cyber-crooks.

The .osiris virus is still infecting computers to this day and regarded as one of the toughest ransomware viruses.

Remove Locky Ransomware and Restore .Osiris Encrypted Files

The first thing that springs up to mind when removing Locky ransomware is to simply delete any files you see. This is highly inadvisable and may further complicate the situation. Instead, malware researchers strongly advise taking a more surgical approach and removing the malicious files using an advanced malware scanner which automatically and swiftly takes care of Locky without any further damage to the files.

After you have removed Locky’s .osiris ransomware virus, the next step for you is to try and restore your files. But, before restoring the files we strongly urge you to create couple of copies of them and then try the methods we have suggested in step “2. Restore files encrypted by Locky .osiris” below. This way you will not risk the actual files why attempting those alternative solutions. Let us know in the comment section below whether or not the solutions worked and do not hesitate to ask us any questions, we will attempt to help to the best of our abilities.


Berta Bilbao

Berta is a dedicated malware researcher, dreaming for a more secure cyber space. Her fascination with IT security began a few years ago when a malware locked her out of her own computer.

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