EFJI ransomware will encrypt all of your files, leaving no access to them
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EFJI is a version of STOP/DJVU file-encrypting computer virus that belongs to ransomware category. This malware variant leverages RSA encryption algorithm to lock all victim’s files on a computer or network. Once encrypted, data files will be appended with additional .efji extension. For instance, a document called 1.doc will appear as 1.doc.efji. Once all files are locked, this ransomware creates and saves _readme.txt ransom notes in every affected file folder. The text file tells that all files were encrypted and the virus’ developers are the only ones who have the decryption tools. In order to purchase them, the victim is instructed to write to helpmanager@mail.ch or restoremanager@airmail.cc emails within 3 days. If the victim pays within 72 hours, the ransom price will be $490, otherwise $980.
We have prepared this in-depth guide on how to remove EFJI ransomware virus from your computer, and explain how to decrypt or recover your files. Please do not pay the ransom as you can never trust the cybercriminals.

_readme.txt lists cybercriminals’ conditions
EFJI ransomware creators seek money, therefore they use encryption to lock victim’s personal files until a ransom is paid. Once the victim discovers that all files became inaccessible, one will notice _readme.txt file is the only one that opens, and it contains instructions from the criminals on how to decrypt data (convert it back to normal).
The _readme.txt file starts with a line reassuring the victim that files are not gone forever and can be restored if criminals’ conditions will be met. To be precise, the criminals want money transferred to them in specific form and way. The criminals state that the victim can still decrypt .efji files if one purchases Bitcoins worth $490 and transfers them to the criminals’ cryptowallet within 3 days. To get full instructions on how to purchase cryptocurrency and the specific wallet address, the note suggests writing to cybercriminals’ email addresses (helpmanager@mail.ch or restoremanager@airmail.cc).
The attackers also promise to decrypt one small file as a proof that they actually have the decryption tools on hand. This technique is used by many ransomware authors such as XATI, MMPA, DHARMA or others to convince the victim to pay up sooner.
Why you shouldn’t pay up, according to infosec specialists
Many cybersecurity experts as well as FBI warns not to pay ransoms for cybercriminals. There are many reasons why you shouldn’t, such as:
- Cybercriminals behind the ransomware only care about your money. They will try to convince you to pay, and once you do as they say, they will move on to another victim.
- If you decide to pay, the attackers will know that you are a victim who is willing to listen to their commands. Therefore, they might try to attack you and extort you in some other way in the future (via email phishing or similarly).
- By paying ransoms to criminals, you sponsor their illegal activities and give them a ticket to luxurious lifestyle as well as well as broadening the scale of their criminal operations. Refuse to pay a ransom!
- There are chances to recover data for free if you’re affected by offline encryption. Learn more about it by moving to the decrypt section of this post.
We suggest you try the recommended data recovery methods first. You might be lucky if you’re affected by offline and not online encryption (You must check if the file in C:/SystemID/PersonalID.txt ends in t1).
What the ransomware did to your files
Victims of ransomware simply must accept the fact that encrypted files means gone files, especially if one does not have data backups. There are various ransomware variants in the wild, but STOP/DJVU authors are pretty skilled criminals, and their program does not contain any flaws that would allow malware researchers to create .efji decryption tool. Plus, this ransomware uses military-grade encryption algorithm to secure your files and prevent access to them.

To understand the concept of ransomware, you should know that encryption algorithms such as RSA or AES, or combinations of both, are used to securely lock confidential information. For example, the majority of information transmitted via Internet is encrypted so that hackers using network sniffer programs wouldn’t be able to read the transferred information. In other words, data encryption is used daily in many information transmission environments. In this scenario, encryption is used by ransomware to extort the victim, by keeping the file decryption key from him and preventing file access until one agrees to pay the ransom.
We strongly encourage you to remove EFJI ransomware virus from the system as soon as you can. This malware is extremely dangerous because it is known for installing AZORULT password-stealer on the system and damaging Windows HOSTS file. To remove virus damage and repair damaged system, we strongly recommend installing and scanning the computer with a well-known computer repair software RESTORO.
Name | EFJI Ransomware Virus |
Type | Crypto-virus; File Locker; Ransomware |
Malicious files | 5FC1.exe, 3dbb.exe, 9B23.tmp.exe (or similar), updatewin.exe |
Dropped files | _readme.txt, PersonalID.txt, all encrypted file versions |
Origins | STOP/DJVU |
Encryption algorithm | RSA |
Version | 258th |
Other versions | LYLI, KOLZ, COPA, BOOP, FOQE, MOSS |
Ransom note | _readme.txt |
Decryption price | $490 in 3 days, $980 if later |
Extension used | .efji |
Criminal contact | helpmanager@mail.ch and restoremanager@airmail.cc |
Detection name examples | TR/Crypt.Agent.dtjce (Avira), Trojan.GenericKDZ.70699 (GData), Ransom:Win32/STOP.BS!MTB (Microsoft), see full list on VT |
Symptoms of infection | Ransomware showcases fake Windows update screen (winupdate.exe process) while it scans and encrypts personal files on the system. The malware marks each affected file with .efji extension and drops _readme.txt note in every folder. The note instructs to contact cybercriminals via provided emails and pay a hefty ransom for data decryption tools. |
Additional damage | This malware is known for its tendency to install AZORULT malware, which mainly functions as a password-stealer. Additional damage will be done to Windows HOSTS file. Learn how to reset HOSTS file here, or use RESTORO to revert changes. |
Distribution | This virus is known to hide in illegal downloads such as KMSPico or software cracks and keygens. |
Removal | Remove the ransomware remains and repair virus damage using RESTORO. You can read its review here. |
Ransomware-type viruses are actively distributed in both 2019 and 2020, and the acceleration of their attack scope is mainly based on the appearance of Ransomware-as-a-Service model (RaaS). We suggest that you read and implement some of our suggested ransomware prevention methods as soon as possible.
Ransomware distributions: main techniques explained
EFJI ransomware is essentially similar to other malware samples because they all are distributed in quite simple ways that rely on victim’s deception. The majority of ransomware are distributed via deceptive email attachments. The criminals use potential target email lists that can be purchased on the dark web for very small sums of money.
The criminals tend to create emails that create a “rush” feeling for the victim. For example, the email suggests opening the attachment which supposedly contains information about a missing or pending payment that needs to be taken care of ASAP. Unfortunately, even if the email attachment appears to be a document, it can contain a malicious script that triggers as soon as the victim enables editing of the file. The script then connects to remote domain and downloads the ransomware payload.
The majority of STOP/DJVU ransomware family versions are distributed via illegal downloads that are extremely popular among regular computer users. For instance, many computer users tend to head to untrustworthy torrent websites to get paid software licenses for free using software cracks and keygens. Unfortunately, such downloads are extremely insecure and also extremely likely to contain malware. These files can be downloaded via popular peer-to-peer file sharing agents such as uTottent, zMule and others. Once the victim opens the deceitful keygen or crack file, the ransomware starts encrypting all files on the system.
For this reason, we recommend you to always download premium software versions from legitimate websites and purchase license keys rather than searching for illegal cracks or other tools online. Additionally, we suggest opening emails send by trusted senders only.
Remove EFJI ransomware virus and recover your data
You must remove EFJI virus from the system safely. For this reason, we suggest free removal guidelines provided below. These instructions cover everything – from booting the computer in secure environment to reporting the cybercrime to legal authorities as well as free decryption software usage guidelines.
After performing EFJI ransomware removal, we suggest you change all of your passwords for accounts saved in your web browser. You must do this in order to protect your online accounts from hacks because the additional malware installed by this ransomware tends to steal login credentials saved in your browser.
Finally, follow the file recovery/decryption tutorial provided at the very end of the article.
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Our team recommends a two-step rescue plan to remove ransomware and other remaining malware from your computer, plus repair caused virus damage to the system:
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EFJI Ransomware Virus Removal Guidelines
Method 1. Enter Safe Mode with Networking
Step 1. Start Windows in Safe Mode with Networking
Before you try to remove EFJI Ransomware Virus virus, you must start your computer in Safe Mode with Networking. Below, we provide the easiest ways to boot PC in the said mode, but you can find additional ones in this in-depth tutorial on our website – How to Start Windows in Safe Mode. Also, if you prefer a video version of the tutorial, check our guide How to Start Windows in Safe Mode on Youtube.
Instructions for Windows XP/Vista/7 users
- First of all, turn off your PC. Then press the Power button to start it again and instantly start pressing F8 button on your keyboard repeatedly in 1-second intervals. This launches the Advanced Boot Options menu.
- Use arrow keys on the keyboard to navigate down to Safe Mode with Networking option and press Enter.
Instructions for Windows 8/8.1/10/11 users
- Open Windows Start menu, then press down the Power button. On your keyboard, press down and hold the Shift key, and then select Restart option.
- This will take you to Windows Troubleshoot screen. Choose Troubleshoot > Advanced Options > Startup Settings > Restart. Tip: If you can't find Startup Settings, click See more recovery options.
- In Startup Settings, press the right key between F1-F9 to enter Safe Mode with Networking. In this case, it is the F5 key.
Step 2. Remove files associated with the virus
Now, you can search for and remove EFJI Ransomware Virus files. It is very hard to identify files and registry keys that belong to the ransomware virus, Besides, malware creators tend to rename and change them repeatedly. Therefore, the easiest way to uninstall such type of a computer virus is to use a reliable security program such as INTEGO Antivirus. For virus damage repair, consider using RESTORO.
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Method 2. Use System Restore
In order to use System Restore, you must have a system restore point, created either manually or automatically.
Step 1. Boot Windows in Safe Mode with Command Prompt
Instructions for Windows XP/Vista/7 users
- Shut down your PC. Start it again by pressing the Power button and instantly start pressing F8 button on your keyboard repeatedly in 1-second intervals. You will see Advanced Boot Options menu.
- Using arrow keys on the keyboard, navigate down to Safe Mode with Command Prompt option and press Enter.
Instructions for Windows 8/8.1/10/11 users
- Launch Windows Start menu, then click the Power button. On your keyboard, press down and hold the Shift key, and then choose Restart option with the mouse cursor.
- This will take you to Windows Troubleshoot screen. Choose Troubleshoot > Advanced Options > Startup Settings > Restart. Tip: If you can't find Startup Settings, click See more recovery options.
- In Startup Settings, press the right key between F1-F9 to enter Safe Mode with Command Prompt. In this case, press F6 key.
Step 2. Start System Restore process
- Wait until system loads and command prompt shows up.
- Type cd restore and press Enter, then type rstrui.exe and press Enter. Or you can just type %systemroot%system32restorerstrui.exe in command prompt and hit Enter.
- This launches System Restore window. Click Next and then choose a System Restore point created in the past. Choose one that was created before ransomware infection.
- Click Yes to begin the system restoration process.
After restoring the system, we recommend scanning the system with antivirus or anti-malware software. In most cases, there won't be any malware remains, but it never hurts to double-check. In addition, we highly recommend checking ransomware prevention guidelines provided by our experts in order to protect your PC against similar viruses in the future.
Alternative software recommendations
Malwarebytes Anti-Malware
Removing spyware and malware is one step towards cybersecurity. To protect yourself against ever-evolving threats, we strongly recommend purchasing a Premium version of Malwarebytes Anti-Malware, which provides security based on artificial intelligence and machine learning. Includes ransomware protection. See pricing options and protect yourself now.
System Mechanic Ultimate Defense
If you're looking for an all-in-one system maintenance suite that has 7 core components providing powerful real-time protection, on-demand malware removal, system optimization, data recovery, password manager, online privacy protection and secure driver wiping technology. Therefore, due to its wide-range of capabilities, System Mechanic Ultimate Defense deserves Geek's Advice approval. Get it now for 50% off. You may also be interested in its full review.
Disclaimer. This site includes affiliate links. We may earn a small commission by recommending certain products, at no additional cost for you. We only choose quality software and services to recommend.
Decrypt EFJI files
Fix and open large EFJI files easily:
It is reported that STOP/DJVU ransomware versions encrypt only the beginning 150 KB of each file to ensure that the virus manages to affect all files on the system. In some cases, the malicious program might skip some files at all. That said, we recommend testing this method on several big (>1GB) files first.
- Create a copy of encrypted file to a separate folder using Copy > Paste commands.
- Now, right-click the created copy and choose Rename. Select the EFJI extension and delete it. Press Enter to save changes.
- In the prompt asking whether you want to make the changes as file might become unusable, click OK.
- Try opening the file.
STOP/DJVU decryption tool usage guide
STOP/DJVU ransomware versions are grouped into old and new variants. EFJI Ransomware Virus is considered the new STOP/DJVU variant, just like DARJ DAZX, TYWD, TYCX, TYOS, TYPO, JYWD (find full list here). This means full data decryption is now possible only if you have been affected by offline encryption key. To decrypt your files, you will have to download Emsisoft Decryptor for STOP DJVU, a tool created and maintained by a genius security researcher Michael Gillespie.
Note! Please do not spam the security researcher with questions whether he can recover your files encrypted with online key - it is not possible.
In order to test the tool and see if it can decrypt EFJI files, follow the given tutorial.
- Download the decryption tool from Emsisoft.
- Click the little arrow next to your download and choose Show in Folder.
- Now, right-click the file and choose Run as Administrator. If asked, enter administrator's password.
- In UAC window, click Yes.
- Click Yes to agree to software terms in both windows.
- The tool will automatically include C:// disk as a location to decrypt. The file recovery tool will prepopulate the locations to scan, including connected data storage drives or network drives. Click Add folder if you wish to add additional locations.
In Options tab, you can choose to keep encrypted file copies. We recommend leaving this option selected, especially if you do not know if the decryption tool will work. - Click Decrypt to start restoring EFJI files. You will see the progress in the Results tab. Here, you can see messages from the tool, such as whether the decryption procedure is successful, or you need to wait for an update.
You might also be informed that online key was used to encrypt your files. In such case, the decryption tool won't work for you, and the only way to recover your files is to use a data backup.
Meanings of decryptor's messages
The EFJI decryption tool might display several different messages after failed attempt to restore your files. You might receive one of the following messages:
Error: Unable to decrypt file with ID: [example ID]
This message typically means that there is no corresponding decryption key in the decryptor's database.
No key for New Variant online ID: [example ID]
Notice: this ID appears to be an online ID, decryption is impossible
This message informs that your files were encrypted with online key, meaning no one else has the same encryption/decryption key pair, therefore data recovery without paying the criminals is impossible.
Result: No key for new variant offline ID: [example ID]
This ID appears to be an offline ID. Decryption may be possible in the future.
If you were informed that an offline key was used, but files could not be restored, it means that the offline decryption key isn't available yet. However, receiving this message is extremely good news, meaning that it might be possible to restore your EFJI extension files in the future. It can take a few months until the decryption key gets found and uploaded to the decryptor. We recommend you to follow updates regarding the decryptable DJVU versions here. We strongly recommend backing up your encrypted data and waiting.
Report Internet crime to legal departments
Victims of EFJI Ransomware Virus should report the Internet crime incident to the official government fraud and scam website according to their country:
- In the United States, go to the On Guard Online website.
- In Australia, go to the SCAMwatch website.
- In Germany, go to the Bundesamt für Sicherheit in der Informationstechnik website.
- In Ireland, go to the An Garda Síochána website.
- In New Zealand, go to the Consumer Affairs Scams website.
- In the United Kingdom, go to the Action Fraud website.
- In Canada, go to the Canadian Anti-Fraud Centre.
- In India, go to Indian National Cybercrime Reporting Portal.
- In France, go to the Agence nationale de la sécurité des systèmes d’information.
If you can't find an authority corresponding to your location on this list, we recommend using any search engine to look up "[your country name] report cyber crime". This should lead you to the right authority website. We also recommend staying away from third-party crime report services that are often paid. It costs nothing to report Internet crime to official authorities.
Another recommendation is to contact your country's or region’s federal police or communications authority.
Frequently Asked Questions
You can only open EFJI files if you have the decryption key, or if you were affected by offline encryption type.
To figure out whether you were affected by offline encryption, please go to C:/SystemID/PersonalID.txt and see if the string inside of it ends in t1. You can also try using Emsisoft Decryptor for STOP/DJVU.
Please follow the guidances provided by the official EFJI decryption tools and believe what they say. If they say it is impossible to decrypt, it really is so. There is no magic tool or human capable of decrypting your files hiding somewhere. Encryption is a technique created to be nearly impossible to decrypt without a special private key (held by the criminals).
We advise scanning with anti-virus, anti-malware, malware removal tools or software like RESTORO to eliminate virus damage on the system. If you do not trust using a single tool, try running one after another. However, we do not recommend keeping several security programs on a computer at once as they can interfere with each other's work.
Beware of fake EFJI decryption tools circulating around the web. Cyber criminals are uploading them to various shady websites, also might be promoting them via suspicious Youtube videos. These programs can infect your computer even more heavily (Trojans, miners, etc.). We suggest being extremely cautious around the web. If there will be an official STOP/DJVU decryption tool available, it will be widely discussed in public media.

Norbert Webb is the head of Geek’s Advice team. He is the chief editor of the website who controls the quality of content published. The man also loves reading cybersecurity news, testing new software and sharing his insights on them. Norbert says that following his passion for information technology was one of the best decisions he has ever made. “I don’t feel like working while I’m doing something I love.” However, the geek has other interests, such as snowboarding and traveling.
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