Prevent data and monetary loss caused by Erenahen ransomware

Also Known As: Erenahen virus
Distribution: Low
Damage level: Severe

Erenahen ransomware removal instructions

What is Erenahen?

Discovered by GrujaRS, Erenahen is malicious software categorized as ransomware. Typically, when computers are infiltrated with programs like Erenahen, people cannot access their files since these programs encode them with strong encryption algorithms. To regain access to their files, victims are encouraged to pay ransoms. I.e., purchase tools and/or keys from the cyber criminals who designed the ransomware. Erenahen renames all encrypted files by adding the ".Erenahen" extension. For example, "1.jpg" becomes "1.jpg.Erenahen".  It also creates a ransom message within the "How_to_open_files.html" file, which contains instructions about how to pay the ransom.

The ransom message states that it is impossible to recover (restore) files without a unique decryptor. Therefore, victims cannot decrypt files encoded by Erenahen without the correct software. To purchase this, victims must contact the developers via the or email address. They are permitted to send one file no larger than 10 MB, which cyber criminals decrypt free of charge. The email must contain a personal ID that is provided in the "How_to_open_files.HTML" file. It is stated that attempts to restore files manually will cause permanent data loss, however, cyber criminals cannot be trusted, since victims who consider paying risk being scammed. In many cases, cyber criminals do not sent decryption tools/keys even after payment. Unfortunately, only ransomware developers have tools that can decode encrypted files. To avoid data loss and being scammed, restore files from a backup if one was created before installation of ransomware.

Screenshot of a message encouraging users to pay a ransom to decrypt their compromised data:

Erenahen decrypt instructions

Erenahen is just one of many ransomware-type programs. Other examples are b00m, Moka, and Kokoklock. Typically, they prevent victims from accessing their files by encrypting them with strong cryptographic algorithms (symmetric or asymmetric). Once this is done, cyber criminals encourage victims to purchase decryption tools and/or keys from them. Generally, only they have these tools/keys and there is no other way to decrypt files, unless ransomware is not complete (contains bugs, flaws, and so on). To avoid data and financial loss caused ransomware-type programs, have data backed up and keep it on a remote server (Cloud) and/or unplugged storage device.

How did ransomware infect my computer?

In most cases cyber criminals proliferate malicious programs such as Erenahen ransomware though spam campaigns, Trojans, fake software updaters, dubious software download sources and unofficial software activation ('cracking') tools. Using spam campaigns, they send emails that contain malicious attachments (or web links that, if clicked, download malicious files). The main goal is to trick recipients into opening the attached file, which then installs malware. The attachments are usually Microsoft Office of PDF documents, archive files (RAR, ZIP), executable files (.exe), JavaScript, and others. Trojans are programs that can cause damage, but only after installation. If installed, they cause chain infections by downloading and installing additional malware. Fake (unofficial) software updaters usually infect systems when they download and install malicious programs rather than updates, or they exploit bugs/flaws of outdated software. Examples of dubious software download channels are P2P (Peer-to-Peer) networks such as eMule, torrent clients, free file hosting websites, freeware (free software) download pages, third party downloaders, unofficial websites, etc. Cyber criminals use these channels to disguise malicious files as legitimate. People who download and open files downloaded from these sources risk installation of malicious software. Software 'cracking' tools supposedly allow users to bypass paid software activation free of charge, however, people who use these tools allow malware to be installed.

Threat Summary:
Name Erenahen virus
Threat Type Ransomware, Crypto Virus, Files locker.
Encrypted Files Extension .Erenahen
Ransom Demanding Message How_to_open_files.html
Cyber Criminal Contact,
Detection Names AVG (Win32:Malware-gen), BitDefender (DeepScan:Generic.Ransom.GlobeImposter.53774E16), ESET-NOD32 (A Variant Of Win32/Filecoder.FV), Kaspersky (HEUR:Trojan.Win32.Generic), Full List Of Detections (VirusTotal)
Symptoms Cannot open files stored on your computer, previously functional files now have a different extension (for example, my.docx.locked). A ransom demand message is displayed on your desktop. Cyber criminals demand payment of a ransom (usually in bitcoins) to unlock your files.
Distribution methods Infected email attachments (macros), torrent websites, malicious ads.
Damage All files are encrypted and cannot be opened without paying a ransom. Additional password-stealing trojans and malware infections can be installed together with a ransomware infection.

To eliminate malware infections our security researchers recommend scanning your computer with Spyhunter.
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How to protect yourself from ransomware infections

Do not open attachments or web links presented in irrelevant emails that are received from unknown, suspicious addresses. All software and files should be downloaded from official websites. Note that unofficial websites, third party downloaders, installers and other tools can be used to distribute files that install malicious programs. Furthermore, software and operating systems should be updated using implemented functions or tools that are created by the official software developers. Software 'cracking'/unofficial activation tools often install malware rather than activating installed programs (even if they do, it is illegal to use them). Protect your system from various threats by regularly scanning it with a reputable anti-virus or anti-spyware suite (and keep it updated at all times). If your computer is already infected with Erenahen, we recommend running a scan with Spyhunter for Windows to automatically eliminate this ransomware.

Text presented in Erenahen ransomware HTML file ("How_to_open_files.html")

Your files are encrypted!
What happened?
Your files are encrypted, and currently unavailable.
You can check it: all files on you computer has new expansion.
By the way, everything is possible to recover (restore), but you need to buy a unique decryptor.
Otherwise, you never cant return your data.

For purchasing a decryptor contact us by email:
If you will get no answer within 24 hours contact us by our alternate emails:

What guarantees?
Its just a business. If we do not do our work and liabilities - nobody will not cooperate with us.
To verify the possibility of the recovery of your files we can decrypted 1 file for free.
Attach 1 file to the letter (no more than 10Mb). Indicate your personal ID on the letter:
ï Attempts of change files by yourself will result in a loose of data.
ï Our e-mail can be blocked over time. Write now, loss of contact with us will result in a loose of data.
ï Use any third party software for restoring your data or antivirus solutions will result in a loose of data.
ï Decryptors of other users are unique and will not fit your files and use of those will result in a loose of data.
ï If you will not cooperate with our service - for us, its does not matter. But you will lose your time and data, cause just we have the private key.

Screenshot of files encrypted by Erenahen (".Erenahen" extension):

Files encrypted by Erenahen

Erenahen ransomware removal:

Instant automatic malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Spyhunter is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:
▼ DOWNLOAD Spyhunter By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

Quick menu:

Step 1

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in "Safe Mode with Networking":

Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in "Safe Mode with Networking":

Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button. In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.

windows 10 safe mode with networking

Video showing how to start Windows 10 in "Safe Mode with Networking":

Step 2

Log in to the account infected with the Erenahen virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.

If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.

Video showing how to remove ransomware virus using "Safe Mode with Command Prompt" and "System Restore":

1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.

Boot your computer in Safe Mode with Command Prompt

2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.

system restore using command prompt type cd restore

3. Next, type this line: rstrui.exe and press ENTER.

system restore using command prompt rstrui.exe

4. In the opened window, click "Next".

restore system files and settings

5. Select one of the available Restore Points and click "Next" (this will restore your computer system to an earlier time and date, prior to the Erenahen ransomware virus infiltrating your PC).

select a restore point

6. In the opened window, click "Yes".

run system restore

7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining Erenahen ransomware files.

To restore individual files encrypted by this ransomware, try using Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of Erenahen are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.

To restore a file, right-click over it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the "Restore" button.

Restoring files encrypted by CryptoDefense

If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode making its removal complicated. For this step, you require access to another computer.

To regain control of the files encrypted by Erenahen, you can also try using a program called Shadow Explorer. More information on how to use this program is available here.

shadow explorer screenshot

To protect your computer from file encryption ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and EasySync CryptoMonitor, which artificially implant group policy objects into the registry to block rogue programs such as Erenahen ransomware.

Note that Windows 10 Fall Creators Update includes a "Controlled Folder Access" feature that blocks ransomware attempts to encrypt your files. By default, this feature automatically protects files stored in the Documents, Pictures, Videos, Music, Favorites as well as Desktop folders.

Controll Folder Access

Windows 10 users should install this update to protect their data from ransomware attacks. Here is more information on how to get this update and add an additional protection layer from ransomware infections.

HitmanPro.Alert CryptoGuard - detects encryption of files and neutralises any attempts without need for user-intervention:

hitmanproalert ransomware prevention application

Malwarebytes Anti-Ransomware Beta uses advanced proactive technology that monitors ransomware activity and terminates it immediately - before reaching users' files:

malwarebytes anti-ransomware

  • The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups. More information on online backup solutions and data recovery software Here.

Other tools known to remove Erenahen ransomware:

About the author:

Tomas Meskauskas

Tomas Meskauskas - expert security researcher, professional malware analyst.

I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats. Contact Tomas Meskauskas.

PCrisk security portal is brought by a company RCS LT. Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.

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Malware activity

Global malware activity level today:

Medium threat activity

Increased attack rate of infections detected within the last 24 hours.

QR Code
Erenahen virus QR code
A QR code (Quick Response Code) is a machine-readable code which stores URLs and other information. This code can be read using a camera on a smartphone or a tablet. Scan this QR code to have an easy access removal guide of Erenahen virus on your mobile device.
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