Home > Ransomware > RotorCrypt Ransomware Removal – Restore .Black_OFFserve Files

RotorCrypt Ransomware Removal – Restore .Black_OFFserve Files

RotorCrypt ransomware image

Our RotorCrypt ransomware removal guide shows how computer users can restore their computers from the dangerous virus. It alters important settings on the system and can lead to further infections. Read our in-depth article to learn more about it.

Threat Summary

Name RotorCrypt
Type Ransomware, Cryptovirus
Short Description The RotorCrypt ransomware is a dangerous virus that assigns .Black_OFFserve extension to the compromised files. The victim’s system is also modified and additional malware can be instituted in them.
Symptoms The victims will notice that a large portion of their data is going to be encrypted with a powerful cipher and renamed using a template extension. They may also experience significant performance issues, application failure and other types of damage.
Distribution Method Spam Emails, Email Attachments
Detection Tool See If Your System Has Been Affected by malware


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User Experience Join Our Forum to Discuss RotorCrypt.
Data Recovery Tool Windows 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.

RotorCrypt Ransomware – Ways of Distribution

The RotorCrypt virus is a well-known example of the the ransomware family that shares the same name. A new virus samples has been identified that appears to be a customized version of prior code.

The current wave of RotorCrypt ransomware is primarily distributed using the traditional delivery methods. Depending on the attack campaign the criminals can opt to use email spam messages by taking advantage of different social engineering tricks. The hackers usually use templates that utilize the spread mechanics. The criminals behind the RotorCrypt virus specifically carrying the .Black_OFFserve extension strain can depend on several tactics when distributing the malware messages:

  • File Attachments — The virus files can be attached directly to the messages as attachments under different names. The victims may be coerced into opening them up by masquerading as useful software or utilities. Advanced tactics use password-protected archives which contain the ransomware strains.
  • Hyperlinks — The criminals can embed links that lead to the Rotorcrypt ransomware executable files. They are usually disguised as password reset links, login pages, confirmation dialogs or other related parts of popular web services.
  • Infected Documents — The criminals can utilize virus documents that may include rich text documents, spreadsheets or presentations of user interest. Once opened the victims will see a notification prompt. It asks them to enable the built-in macros (scripts). If this is done the infection is downloaded from a remote location and started on the local machine.

Another popular tactic for spreading malware is the creation of hacker-controlled sites. They may pose as legitimate download sites, search engines or vendors and attempt to deliver the virus file. A large part of them actually contain malware software installers. They represent modified setup files taken from the official vendors. The hacker operators behind the .Black_OFFserve virus hijack them and include the malware component. The resulting installer is then uploaded to the relevant hacker-operated site.

The hacker-controlled sites can also be found via browser hijacker instances. Users can get redirected to the via ads, scripts and banners placed on other sites or through a browser hijacker. They are malware extensions made for the most popular web browsers. Usually the list includes the following applications: Mozilla Firefox, Google Chrome, Safari, Microsoft Edge, Opera and Internet Explorer. Their standard behavior patterns are to redirect the victims to the hacker-controlled download page or directly deliver the infection automatically. They are especially dangerous as they can be further modified to cause other system changes as well.

RotorCrypt Ransomware – In-Depth Description

The RotorCrypt ransomware has been spotted in a new attack campaign. The new strain uses the .Black_OFFserve extension to differentiate itself from prior samples. Like all updated versions it is a customized variant of the original code and as such follows the same behavior patterns.

After infection the samples do not immediately begin to alter the system but delay the virus execution. This is part of the malware family’s stealth protection mechanism. It delays the virus infection on purposes in order to evade any signature and behavior scans that may be running. Another strategy that can be employed can also scan the system for any running security software (anti-virus products, sandbox and debug environments, as well as virtual machines). If found their real-time engines can be disabled or completely removed. Depending on the hacker configuration the virus may delete itself to avoid detection.

One this is done the malware engine hooks itself to system processes and hides itself in the Microsoft Windows system folder as a legitimate component. The security experts have been able to identify several prior attack campaigns that hide their tracks from the system itself as well.

If the samples associated with the .Black_OFFserve extension are direct derivatives they can suppress the error messages that are the result of its execution. The next step in the behavior pattern is the detailed information gathering process. It aims to extract two main types of data that is directly sent to the hacker operators:

  • Anonymous Metrics — This type of information refers to system information that is collected for statistical purposes by the hackers. Example data usually includes operating system version and date and time of the infections.
  • Personally-identifiable Data — The malware engine can extract information that can directly expose the users identity. This may include their names, address, preferences, interests and etc.

System changes can also impact the Windows Registry by manipulating existing values or creating new ones. This step may be part of the persistent state of execution which is achieved. It allows the malware instance to automatically block manual user removal attempts by constantly monitoring their behavior. It can also interact with the Windows volume manager which allows the ransomware component to affect files located on remoovable storage devices and available network shares as well.

Such infections can be bundled alongside Trojan code which allows the hackers to spy on the victims in real time as well as take over control of their machines at any given time.

An additional danger is the fact that the RotorCrypt ransomware samples can retrieve all data files prior to the encryption phase. This is especially useful when the hackers attempt blackmail strategies upon the victims.

The malware component also deletes all found Shadow Volume copies which makes it more difficult for the users to restore their files. In these cases a professional data recovery solution needs to be used as well.

RotorCrypt Ransomware – Encryption Process

Once all infections have complete the ransomware component is started. It is able to encrypt user files according to a built-in list of target file type extensions.

A sample list retrieved from earlier versions targets the following data:

.1cd, .avi, .bak, .bmp, .cf, .cfu, .csv, .db, .dbf, .djvu, .doc, .docx, .dt, .elf, .epf, .erf, .exe,
.flv, .geo, .gif, .grs, .jpeg, .jpg, .lgf, .lgp, .log, .mb, .mdb, .mdf, .mxl, .net, .odt, .pdf, .png,
.pps, .ppt, .pptm, .pptx, .psd, .px, .rar, .raw, .st, .sql, .tif, .txt, .vob, .vrp, .xls, .xlsb, .xlsx,
.xml, .zip

A notable addition to the file type extensions are several extensions that are used against book keeping and business software. It is very likely that the criminal operators initiate attacks against such victims.

Depending on the exact campaign that victims can receive different ransomware notes. They are frequently tweaked according to the victim users. A generic message retrieved from one of the samples reads the following:

Good day
Your files were encrypted/locked
As evidence can decrypt file 1 to 3 1-30MB
The price of the transcripts of all the files on the server: 7 Bitcoin
Recommend to solve the problem quickly and not to delay
Also give advice on how to protect Your server against threats from the network
(Files sql mdf backup decryption strictly after payment)!

The current active campaign assigns the following extension to the victim files: !==SOLUTION OF THE PROBLEM==blacknord@tutanota.com==.Black_OFFserve.

Previous Rotorcrypt ransomware attacks were found to feature these renaming schemes:

  • !_____LIKBEZ77777@GMAIL.COM____.c400
  • !_____GEKSOGEN911@GMAIL.COM____.c300
  • .-.directorat1c@gmail.com.roto
  • .-.CRYPTSb@GMAIL.COM.roto>
  • !-==kronstar21@gmail.com=–.crypt>
  • !==helpsend369@gmail.com==.crypt>
  • !__crypthelp12@gmail.com_.crypt
  • !___prosschiff@gmail.com_.crypt>
  • !____moskali1993@mail.ru___.crypt>
  • !______sufnex331@gmail.com______.crypt
  • !______bigromintol971@gmail.com______.crypt
  • !_______GASWAGEN123@GMAIL.COM____.crypt
  • !_________pkigxdaq@bk.ru_______.crypt
  • !______________DESKRYPTEDN81@GMAIL.COM.crypt

Remove RotorCrypt Ransomware and Restore .Black_OFFserve Files

If your computer got infected with the RotorCrypt ransomware virus, you should have a bit of experience in removing malware. You should get rid of this ransomware as quickly as possible before it can have the chance to spread further and infect other computers. You should remove the ransomware and follow the step-by-step instructions guide provided below.

Martin Beltov

Martin graduated with a degree in Publishing from Sofia University. As a cyber security enthusiast he enjoys writing about the latest threats and mechanisms of intrusion.

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Step 1: Scan for RotorCrypt with SpyHunter Anti-Malware Tool

1. Click on the "Download" button to proceed to SpyHunter's download page.

It is recommended to run a scan before purchasing the full version of the software to make sure that the current version of the malware can be detected by SpyHunter. Click on the corresponding links to check SpyHunter's EULA, Privacy Policy and Threat Assessment Criteria.

2. After you have installed SpyHunter, wait for it to update automatically.

scan for and delete ransomware virus step 2

3. After the update process has finished, click on the 'Malware/PC Scan' tab. A new window will appear. Click on 'Start Scan'.

scan for and delete ransomware virus step 3

4. After SpyHunter has finished scanning your PC for any files of the associated threat and found them, you can try to get them removed automatically and permanently by clicking on the 'Next' button.

scan for and delete ransomware virus step 4

If any threats have been removed, it is highly recommended to restart your PC.

Ransomware Automatic Removal - Video Guide

Step 2: Uninstall RotorCrypt and related malware from Windows

Here is a method in few easy steps that should be able to uninstall most programs. No matter if you are using Windows 10, 8, 7, Vista or XP, those steps will get the job done. Dragging the program or its folder to the recycle bin can be a very bad decision. If you do that, bits and pieces of the program are left behind, and that can lead to unstable work of your PC, errors with the file type associations and other unpleasant activities. The proper way to get a program off your computer is to Uninstall it. To do that:

1. Hold the Windows Logo Button and "R" on your keyboard. A Pop-up window will appear.
delete ransomware from windows step 1

2. In the field type in "appwiz.cpl" and press ENTER.
delete ransomware from windows step 2

3. This will open a window with all the programs installed on the PC. Select the program that you want to remove, and press "Uninstall"
delete ransomware from windows step 3Follow the instructions above and you will successfully delete most unwanted and malicious programs.

Step 3: Clean any registries, created by RotorCrypt on your computer.

The usually targeted registries of Windows machines are the following:

  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce

You can access them by opening the Windows registry editor and deleting any values, created by RotorCrypt there. This can happen by following the steps underneath:

1. Open the Run Window again, type "regedit" and click OK.
delete ransomware virus registries step 1

2. When you open it, you can freely navigate to the Run and RunOnce keys, whose locations are shown above.
delete ransomware virus registries step 2

3. You can remove the value of the virus by right-clicking on it and removing it.
delete ransomware virus registries step 3 Tip: To find a virus-created value, you can right-click on it and click "Modify" to see which file it is set to run. If this is the virus file location, remove the value.

Before starting "Step 4", please boot back into Normal mode, in case you are currently in Safe Mode.
This will enable you to install and use SpyHunter 5 successfully.

Step 4: Boot Your PC In Safe Mode to isolate and remove RotorCrypt


Manual Removal Usually Takes Time and You Risk Damaging Your Files If Not Careful!
We Recommend To Scan Your PC with SpyHunter

Keep in mind, that SpyHunter’s scanner is only for malware detection. If SpyHunter detects malware on your PC, you will need to purchase SpyHunter's malware removal tool to remove the malware threats. Read our SpyHunter 5 review. Click on the corresponding links to check SpyHunter's EULA, Privacy Policy and Threat Assessment Criteria

1. Hold Windows Key + R.
remove ransomware in safe mode step 1

2. The "Run" Window will appear. In it, type "msconfig" and click OK.
remove ransomware in safe mode step 2

3. Go to the "Boot" tab. There select "Safe Boot" and then click "Apply" and "OK".
remove ransomware in safe mode step 3
Tip: Make sure to reverse those changes by unticking Safe Boot after that, because your system will always boot in Safe Boot from now on.

4. When prompted, click on "Restart" to go into Safe Mode.
remove ransomware in safe mode step 4

5. You can recognise Safe Mode by the words written on the corners of your screen.
remove ransomware in safe mode step 5

Step 5: Try to Restore Files Encrypted by RotorCrypt.

Method 1: Use STOP Decrypter by Emsisoft.

Not all variants of this ransomware can be decrypted for free, but we have added the decryptor used by researchers that is often updated with the variants which become eventually decrypted. You can try and decrypt your files using the instructions below, but if they do not work, then unfortunately your variant of the ransomware virus is not decryptable.

Follow the instructions below to use the Emsisoft decrypter and decrypt your files for free. You can download the Emsisoft decryption tool linked here and then follow the steps provided below:

1 Right-click on the decrypter and click on Run as Administrator as shown below:

stop ransomware decryptor step 1

2. Agree with the license terms:

stop ransomware decryptor step 2

3. Click on "Add Folder" and then add the folders where you want files decrypted as shown underneath:

stop ransomware decryptor step 3

4. Click on "Decrypt" and wait for your files to be decoded.

stop ransomware decryptor step 4

Note: Credit for the decryptor goes to Emsisoft researchers who have made the breakthrough with this virus.

Method 2: Use data recovery software

Ransomware infections and RotorCrypt aim to encrypt your files using an encryption algorithm which may be very difficult to decrypt. This is why we have suggested a data recovery method that may help you go around direct decryption and try to restore your files. Bear in mind that this method may not be 100% effective but may also help you a little or a lot in different situations.

1. Download the recommended Data Recovery software by clicking on the link underneath:

Simply click on the link and on the website menus on the top, choose Data Recovery - Data Recovery Wizard for Windows or Mac (depending on your OS), and then download and run the tool.


What is RotorCrypt Ransomware?

RotorCrypt is a ransomware infection - the malicious software that enters your computer silently and blocks either access to the computer itself or encrypt your files. 

Many ransomware viruses use sophisticated encryption algorithms to make your files inaccessible. The goal of ransomware infections is to demand that you pay a ransom payment to get access to your files back.

What Does RotorCrypt Ransomware Do?

Ransomware in general is a malicious software that is designed to block access to your computer or files until a ransom is paid.

Ransomware viruses can also damage your system, corrupt data and delete files, resulting in the permanent loss of important files.

How Does RotorCrypt Infect?

Via several ways.RotorCrypt Ransomware infects computers by being sent via phishing emails, containing virus attachment. This attachment is usually masked as an important document, like an invoice, bank document or even a plane ticket and it looks very convincing to users.

Another way you may become a victim of RotorCrypt is if you download a fake installer, crack or patch from a low reputation website or if you click on a virus link. Many users report getting a ransomware infection by downloading torrents.

How to Open .RotorCrypt files?

You can't without a decryptor. At this point, the .RotorCrypt files are encrypted. You can only open them once they are decrypted using a specific decryption key for the particular algorithm.

What to Do If a Decryptor Does Not Work?

Do not panic, and backup the files. If a decryptor did not decrypt your .RotorCrypt files successfully, then do not despair, because this virus is still new.

Can I Restore ".RotorCrypt" Files?

Yes, sometimes files can be restored. We have suggested several file recovery methods that could work if you want to restore .RotorCrypt files. 

These methods are in no way 100% guaranteed that you will be able to get your files back. But if you have a backup, your chances of success are much greater.

How To Get Rid of RotorCrypt Virus?

The safest way and the most efficient one for the removal of this ransomware infection is the use a professional anti-malware program.

It will scan for and locate RotorCrypt ransomware and then remove it without causing any additional harm to your important .RotorCrypt files.

Can I Report Ransomware to Authorities?

In case your computer got infected with a ransomware infection, you can report it to the local Police departments. It can help authorities worldwide track and determine the perpetrators behind the virus that has infected your computer.

Below, we have prepared a list with government websites, where you can file a report in case you are a victim of a cybercrime:

Cyber-security authorities, responsible for handling ransomware attack reports in different regions all over the world:

Germany - Offizielles Portal der deutschen Polizei

United States - IC3 Internet Crime Complaint Centre

United Kingdom - Action Fraud Police

France - Ministère de l'Intérieur

Italy - Polizia Di Stato

Spain - Policía Nacional

Netherlands - Politie

Poland - Policja

Portugal - Polícia Judiciária

Greece - Cyber Crime Unit (Hellenic Police)

India - Mumbai Police - CyberCrime Investigation Cell

Australia - Australian High Tech Crime Center

Reports may be responded to in different timeframes, depending on your local authorities.

Can You Stop Ransomware from Encrypting Your Files?

Yes, you can prevent ransomware. The best way to do this is to ensure your computer system is updated with the latest security patches, use a reputable anti-malware program and firewall, backup your important files frequently, and avoid clicking on malicious links or downloading unknown files.

Can RotorCrypt Ransomware Steal Your Data?

Yes, in most cases ransomware will steal your information. It is a form of malware that steals data from a user's computer, encrypts it, and then demands a ransom in order to decrypt it.

In many cases, the malware authors or attackers will threaten to delete the data or publish it online unless the ransom is paid.

Can Ransomware Infect WiFi?

Yes, ransomware can infect WiFi networks, as malicious actors can use it to gain control of the network, steal confidential data, and lock out users. If a ransomware attack is successful, it could lead to a loss of service and/or data, and in some cases, financial losses.

Should I Pay Ransomware?

No, you should not pay ransomware extortionists. Paying them only encourages criminals and does not guarantee that the files or data will be restored. The better approach is to have a secure backup of important data and be vigilant about security in the first place.

What Happens If I Don't Pay Ransom?

If you don't pay the ransom, the hackers may still have access to your computer, data, or files and may continue to threaten to expose or delete them, or even use them to commit cybercrimes. In some cases, they may even continue to demand additional ransom payments.

Can a Ransomware Attack Be Detected?

Yes, ransomware can be detected. Anti-malware software and other advanced security tools can detect ransomware and alert the user when it is present on a machine.

It is important to stay up-to-date on the latest security measures and to keep security software updated to ensure ransomware can be detected and prevented.

Do Ransomware Criminals Get Caught?

Yes, ransomware criminals do get caught. Law enforcement agencies, such as the FBI, Interpol and others have been successful in tracking down and prosecuting ransomware criminals in the US and other countries. As ransomware threats continue to increase, so does the enforcement activity.

About the RotorCrypt Research

The content we publish on SensorsTechForum.com, this RotorCrypt how-to removal guide included, is the outcome of extensive research, hard work and our team’s devotion to help you remove the specific malware and restore your encrypted files.

How did we conduct the research on this ransomware?

Our research is based on an independent investigation. We are in contact with independent security researchers, and as such, we receive daily updates on the latest malware and ransomware definitions.

Furthermore, the research behind the RotorCrypt ransomware threat is backed with VirusTotal and the NoMoreRansom project.

To better understand the ransomware threat, please refer to the following articles which provide knowledgeable details.

As a site that has been dedicated to providing free removal instructions for ransomware and malware since 2014, SensorsTechForum’s recommendation is to only pay attention to trustworthy sources.

How to recognize trustworthy sources:

  • Always check "About Us" web page.
  • Profile of the content creator.
  • Make sure that real people are behind the site and not fake names and profiles.
  • Verify Facebook, LinkedIn and Twitter personal profiles.

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