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

REPAIR VIRUS DAMAGE 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 a two-step rescue plan to remove ransomware and other remaining malware from your computer, plus repair caused virus damage to the system: 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. Get INTEGO ANTIVIRUS for Windows to remove ransomware, Trojans, adware and other spyware and malware variants and protect your PC and network drives 24/7. This VB100-certified security software uses state-of-art technology to provide protection against ransomware, Zero-Day attacks and advanced threats, Intego Web Shield blocks dangerous websites, phishing attacks, malicious downloads and installation of potentially unwanted programs. Use INTEGO Antivirus to remove detected threats from your computer. Read full review here. 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. Read full review here.

Method 1. Enter 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 Instructions for Windows 8/8.1/10/11 users 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. For virus damage repair, consider using RESTORO.

Method 2. Use System Restore

In order to use System Restore, you must have a system restore point, created either manually or automatically. Instructions for Windows XP/Vista/7 users Instructions for Windows 8/8.1/10/11 users 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 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.

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 BPTO, ISWR, ISZA, BPSM, ZOUU, MBTF, ZNSM (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.

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.

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.