Remove OOPU Ransomware Virus (DECRYPT .oopu FILES)

remove OOPU ransomware virus and learn how to decrypt or repair files with .oopu extension (free guide)

OOPU ransomware overview and how it affects files on your computer

Contents

OOPU ransomware overview and how it affects files on your computer
How computers get infected with ransomware and how to prevent it
Remove OOPU ransomware virus and restore your data
Decrypt OOPU files
Frequently Asked Questions

OOPU ransomware is a file-encrypting computer virus that seeks to infiltrate unprotected systems and make user’s files unusable. It is a confirmed variant of STOP/DJVU ransomware group and it uses .oopu extension to mark encrypted files. To illustrate, files that were originally named 1.jpg or 2.docx will appear as 1.jpg.oopu and 2.docx.oopu after the computer gets compromised. Once the virus achieves what it was programmed to do, it drops _readme.txt, also referred to as “ransom notes” in several data folders. This note holds a message from perpetrators responsible for the ransomware attack.

The idea behind this ransomware is to infect computers by deceit, as cybercriminals typically distribute in a form of a software cracks or torrents. After opening an alleged setup, the user’s computer gets severely compromised not only by this ransomware, but also with additional Remote Access Trojans (RATs) and we will discuss these later. The primary aim of the attack is to extort the computer user after taking one’s files hostage.

The _readme.txt note suggests the victim has to pay a ransom

The ransom note dropped by the virus is named _readme.txt and it starts with an explanation that the user can still recover all of one’s files. However, the criminals suggest that there is no other way but paying the ransom, or, as they put it, purchasing the OOPU file decryption tool and private key from them.

The note explains that the victim has to reach out to the ransomware operators via provided email addresses: support@bestyourmail.ch or datarestorehelp@airmail.cc. Additionally, the victim can test the decryption service on one small encrypted file that doesn’t contain any valuable information. In order to do this, one has to attach the file sample to the email and also include the victim’s Personal ID that is provided at the end of the _readme.txt file. The criminals promise to reply and attach a decrypted file version, as well as instructions on how to pay the ransom.

For those wondering about the amount demanded by the cybercriminals, the note clarifies how the payment system works. The crooks explain that the full price of the decryption tools is $980, however, the perpetrators are willing to provide a 50% discount for those who rush to contact them within 72 hours (3 full days). If the computer user does so, the ransom demand will be lowered to $490. However, the crooks won’t accept any other payment method other than those made with cryptocurrency (Bitcoin), because this ensures that law enforcement agencies cannot track the criminals down through transactions.

No matter how prompting the promises of cybercriminals may sound, you should NOT PAY THE RANSOM. This is advised by our team of cybersecurity experts and the same idea is also expressed by the FBI and many other reputable law enforcement agencies and cybersecurity professionals. Paying up is not a solution because it never guarantees data recovery, besides, it puts you at risk because cybercriminals tend to repeatedly target those willing to pay up.

Additional threats installed: protect your computer now

File-encrypting virus that comes as the primary threat is known to travel in tandem with several well-known Remote Access Trojans, most frequently those under the names of Vidar and AZORult. Both of these threats are extremely dangerous as they are capable of collecting and transmitting various sensitive details from victim’s computer to the cybercriminals’ server. Some of the data that these threats steal include browser-saved passwords, cookies, browsing history, autofill data, banking and credit card details. These RATs can also dig for cryptocurrency wallet information, capture screenshots and this way steal private conversations. On top of that, this threat can steal cryptocurrency coins from offline wallets.

That being said, it is important that you remove OOPU ransomware virus along with Trojans installed alongside it. For this task, we recommend that you set up your computer in Safe Mode with Networking and then run a genuine antivirus solution. Next, you may want to download RESTORO (secure download link) and use it to repair virus damage on components and files of Windows OS. Finally, we strongly advise that you take action to protect sensitive data that may has been stolen by the malware. Therefore, you must change all of your passwords associated with the infected computer.

Ransomware Summary

Name	OOPU Ransomware Virus
Type	Ransomware; Crypto-malware; Virtual Extortion Virus
Family	STOP/DJVU
Encryption type	RSA 2048 + Salsa20
Previous versions	QQRI, QQPP, QQJJ, QQKK, OOVB, OODT (find full list here)
Version	550th
Extension	.oopu
Cybercriminal emails	support@bestyourmail.ch, datarestorehelp@airmail.cc
Additional malware dropped	Azorult or Vidar Trojan
Damage	The ransomware uses encryption to maliciously modify all files on the PC and marks their original names with .oopu extension. Ransom notes called as _readme.txt will be dropped in every computer folder. This piece of malware usually drags VIDAR Stealer alongside it and also eliminates VSS from the system. On top of that, it tends to modify Windows HOSTS file to restrict computer user’s access to cybersecurity-related websites online.
Ransom note	_readme.txt
Ransom demand	$490-$980 in Bitcoin
Distribution	Victims often download this ransomware along illegal torrent downloads, cracked software, activators, key generators or tools like KMSPico.
Known software cracks to contain this malware	Corel Draw, Tenorshare 4ukey, Adobe Photoshop, Cubase, Adobe Illustrator, Internet Download Manager, Tally, League of Legends.
Detection names	Trojan:Win32/Sabsik.FL.B!ml (Microsoft), UDS:DangerousObject.Multi.Generic (Kaspersky), Trojan.MalPack.GS (Malwarebytes), ML.Attribute.HighConfidence (Symantec) see all detection name variations on VirusTotal
Removal	Remove ransomware and related malware from your PC using trustworthy software. To repair virus damage on Windows OS files, consider scanning with RESTORO (secure download link).

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Scan your system for FREE to detect security, hardware and stability issues. You can use the scan results and try to remove threats manually, or you can choose to get the full version of software to fix detected issues and repair virus damage to Windows OS system files automatically. Includes Avira spyware/malware detection & removal engine.

The screenshot shown below demonstrates how encrypted files look like.

How computers get infected with ransomware and how to prevent it

Cybercriminals use a couple of common malware distribution methods to spread STOP/DJVU ransomware variants as well as other threats. Variants like OOPU file virus can be found in disguise of software cracks advertised via rogue websites. These websites usually suggest they offer “100% working and full software versions” and that the user can download them via direct link or a torrent. The site includes posts luring users with various popular software and game versions, claiming each of them is available free of cost. Unfortunately, whoever falls for this bait ends up downloading a fake setup file that launches the malware on the computer.

Users should avoid crack and warez sites and instead visit official software vendor’s or partner’s website to get a genuine and legitimate version of a desired computer program or a game. Attempts to bypass license fees can end up in severe computer infection, one that is often times unnoticeable at first.

Another popular method to spread ransomware is by attaching a malicious file to a phishing email. Scammers try to trick unsuspecting user’s by pretending to be someone from their work, legitimate and well-known company, parcel delivery service or an online shop. Scammers pretend they are writing on purpose of delivering an order summary, invoice or a subscription renewal. If the victim falls for the deceit and opens the attached file, the computer gets compromised due to the malicious scripts included in it.

Finally, computer users who have fallen victims to this ransomware should avoid rogue sites claiming they provide “online key DJVU decryption tools.” You can find relevant information about ways to recover or repair your files or even decrypt them (if possible) in this guide for STOP/DJVU victims. Bear in mind that the only firms we acknowledge as trustworthy to repair/decrypt your files are Emsisoft and DiskTuna.

Remove OOPU ransomware virus and restore your data

If you have accidentally downloaded this malware to your computer without realising the risk of pirated software downloads, you should take steps outlined below to remove OOPU ransomware virus and protect your computer ASAP. Follow the directions and do not forget to download RESTORO afterward to see if any of the files belonging to the Windows OS can be decrypted.

Once the computer is cleansed from threats, change all of your passwords.

OUR GEEKS RECOMMEND

Our team recommends removing malware using a professional antivirus software and then using the following tool to repair virus damage to Windows system files:

REPAIR VIRUS DAMAGE TO YOUR COMPUTER

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RESTORO provides a free scan that helps to identify hardware, security and stability issues and presents a comprehensive report which can help you to locate and fix detected issues manually. It is a great PC repair software to use after you remove malware with professional antivirus. The full version of software will fix detected issues and repair virus damage caused to your Windows OS files automatically.

RESTORO uses AVIRA scanning engine to detect existing spyware and malware. If any are found, the software will eliminate them.

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GeeksAdvice.com editors select recommended products based on their effectiveness. We may earn a commission from affiliate links, at no additional cost to you. Learn more.

OOPU 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 OOPU 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 OOPU 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, which also includes data recovery software. 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

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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 OOPU files

Fix and open large OOPU 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 OOPU 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. OOPU Ransomware Virus is considered the new STOP/DJVU variant, just like QQRI, QQPP, QQJJ, QQKK, OOVB, OODT (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 OOPU 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 OOPU 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 OOPU 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 OOPU 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 OOPU 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

✓ How can I open .OOPU files?

You can only open OOPU files if you have the decryption key, or if you were affected by offline encryption type.

✓ How do I know if my files were encrypted with offline or online encryption?

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.

✓ My files contain very important information (family memories). Every tool I used says it is impossible to decrypt. What should I do?

Please follow the guidances provided by the official OOPU 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).

✓ I am afraid virus is still in my computer system. What should I do?

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.

✓ I saw several Youtube videos suggesting secret decryption tools. Can I trust them?

Beware of fake OOPU 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

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.