What is SunnyDay Ransomware?
SunnyDay is a malicious program that has been reported to infect computer systems and restrict access to personal files. It is currently circling around the web in active attack campaigns. The virus adjusts essential system settings. As a consequence, the overall system security is lowered. The worst impact is the encryption of personal files. Encryption of personal files leads to changes in both their code and their names. A file originally named cover.jpg will be renames to cover.jpg.SunnyDay after being encrypted by the ransomware. Based on all nasty issues, hackers try to extort a hefty ransom fee from victims. Supposedly, their decryption tool for .SunnyDay files will restore data and enable you to use it again.
Beware that any negotiations with cybercriminals suggested by the ransom message !-Recovery_Instructions-!.txt should be avoided. Keep up with this article to learn more information about the SunnyDay ransomware virus, discover how to remove it step-by-step, and check out some alternative data recovery methods.

SunnyDay Summary
Name | SunnyDay also known as Generic.Ransom.LockCrypt.3.C0267EF9, Win64:RansomX-gen [Ransom], Ransom:Win32/Filecoder.AA!MTB |
Type | Ransomware, Cryptovirus |
Short Description | A data locker ransomware that utilizes strong cihper algorithms like RSA and AES to encrypt valuable files. Then it demands a ransom for their decryption. |
Symptoms | Important files are locked and renamed with the extension .SunnyDay. A ransom message appears on the computer to request a ransom fee for a decryption tool. |
Distribution Method | Spam Emails, Email Attachments, Torrents |
Detection Tool |
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SunnyDay Virus – How Did I Get It?
To get SunnyDay ransomware on your PC, you need to run its payload file without noticing. The methods that may initiate the attack are different but the most preferred by hacker is malspam (email spam campaigns). Other shady methods that can trick you to run ransomware on your computer include:
- Software cracks;
- Malicious web links;
- Freeware featuring compromised installers;
- Fake software update notifications, etc.
All listed methods attempt to hide the malicious program so that people can run it without suspecting the damage it will cause to their devices and personal data.
SunnyDay Virus – What Does It Do?
The activation of the payload file of the SunnyDay virus is not enough for the completion of all attack stages. The ransomware needs to establish additional malicious files on the system and then start executing them one by one to compromise all system settings that could support the infection flow. The complex attack leads to lots of nasty changes that continue impacting system security until the complete removal of the ransomware from the infected PC.
When SunnyDay ransomware reaches the data encryption stage, it utilizes a built-in cipher module designed to transform parts of the original code of target files. By the use of strong cipher algorithms like AES and RSA the ransomware locks your personal files and prevents you from accessing data they store.
All of the following types of files may be encrypted by the threat:
- Audio files;
- Document files;
- Video files;
- Backup files;
- Image files;
- Banking credentials, etc.
Files corrupted by SunnyDay ransomware are all marked with a specific extension of the same name. The .SunnyDay suffix appended to the original names of some of your files is a sure sign that they have been compromised by the cryptovirus.
Analyses of the code of SunnyDay ransomware reveal that the ransomware misuses registry keys for their special functionalities that control the automatic execution of certain files every time the OS loads. The ransomware compromises the following directories to run its malicious files automatically:
→ 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
Just like other ransomware strains discovered in the wild SunnyDay ransomware drops its ransom note file on the system at the end of the attack. The file could show up on the screen to inform you the following:
! YOUR NETWORK HAS BEEN COMPROMISED !
All your important files have been encrypted!
ANY ATTEMPT TO RESTORE A FILE WITH THIRD-PARTY SOFTWARE WILL PERMANENTLY CORRUPT IT.No software available on internet can help you. We are the only ones able to solve your problem.
We gathered data from different segment of your network. These data are currently stored on a private server and will be immediately destroyed after your payment.
If you decide to not pay, we will keep your data stored and contact press or re-seller or expose it on our partner’s website.
We only seek money and do not want to damage your reputation or prevent your business from running.
If you take wise choice to pay, all of this will be solved very soon and smoothly.
You will can send us 2-3 non-important files and we will decrypt it for free to prove we are able to give your files back.
Contact us.
restoreassistance_net@wholeness.business
restoreassistance_net@decorous.cyou
In the subject write – id-VA0328497918
It is stored on the infected machine under the name !-Recovery_Instructions-!.txt. The message has the purpose to persuade you to contact malware authors and ask them how to transfer a ransom fee, probably in any cryptocurrency.
Keep in mind that hackers who stand behind nasty SunnyDay ransomware attacks cannot be trusted. They could steal your money by providing no effective decryption solution for .SunnyDay files. And a ransom payment does not guarantee the recovery of .SunnyDay files. This step should be avoided. Don’t risk your security and privacy by negotiating with cybercriminals.

Remove SunnyDay Ransomware
The so-called SunnyDay ransomware is a threat with highly complex code that disrupts system security in order to encrypt personal files. Hence, the infected system could be used in a secure manner again only after you remove all malicious files and objects created by the ransomware. All steps presented in the ransomware removal guide below aim to help you to remove malicious files from your infected PC in full.
Beware that manual ransomware removal is suitable for more experienced computer users. If you don’t feel comfortable with the manual steps navigate to the automatic part of the guide. It is also worth mentioning that personal data remains encrypted even after the complete removal of SunnyDay ransomware.
Step 1: Boot Your PC In Safe Mode to isolate and remove SunnyDay





Step 2: Uninstall SunnyDay 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:



Step 3: Clean any registries, created by SunnyDay 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 SunnyDay there. This can happen by following the steps underneath:



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: Scan for SunnyDay with SpyHunter Anti-Malware Tool
Ransomware Automatic Removal - Video Guide
Step 5 (Optional): Try to Restore Files Encrypted by SunnyDay.
Ransomware infections and SunnyDay 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.
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.
SunnyDay FAQ
What is SunnyDay Ransomware?
SunnyDay 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.
Can SunnyDay Ransomware Damage My Computer?
Yes, ransomware can damage your computer. Ransomware is a malicious software that is designed to block access to your computer or files until a ransom is paid. It can encrypt your files and make them inaccessible, preventing you from using your computer or accessing your data. Ransomware can also damage your system, corrupt data and delete files, resulting in the permanent loss of important files.
Should I Ignore Ransomware, like SunnyDay?
No, you should never ignore ransomware. Ransomware can encrypt your data and block access to your computer, making it impossible to access your files until you pay a ransom. Ignoring ransomware could lead to the permanent loss of your data, as well as the potential for the ransomware to spread to other computers on your network. Additionally, paying the ransom does not guarantee that your data will be recovered. The best way to protect yourself is to invest in robust cyber security measures, such as backup solutions and anti-malware software.
How Does SunnyDay Ransomware Infect My Computer?
Via several ways.SunnyDay 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.
After you download and execute this attachment, a drive-by download occurs and your computer is infected with the ransomware virus.
Another way you may become a victim of SunnyDay 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 .SunnyDay files?
You can't. At this point, the .SunnyDay files are encrypted. You can only open them once they are decrypted using a specific decryptionkey for the particular algorithm.
What to Do If Ransomware Decryptor Does Not Work?
Do not panic, and backup the files. If a decryptor did not decrypt your .SunnyDay files successfully, then do not despair, because this virus is still new.
One way to restore files, encrypted by SunnyDay ransomware is to use a decryptor for it. But since it's a new virus, be advised that the decryption keys for it may not be out yet and available to the public. We will update this article and keep you posted as soon as this decryptor is released.
Can I Restore ".SunnyDay" Files (Other Methods)?
Yes, sometimes files can be restored. We have suggested several file recovery methods that could work if you want to restore .SunnyDay 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 Do I Get Rid of SunnyDay Ransomware 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 SunnyDay ransomware and then remove it without causing any additional harm to your important .SunnyDay files.
Also, keep in mind that viruses like SunnyDay ransomware also install Trojans and keyloggers that can steal your passwords and accounts. Scanning your computer with anti-malware software will make sure that all of these virus components are removed and your computer is protected in the future.
What to Do If I Cannot Recover Ransomware Encrypted Files?
There is still a lot you can do. If none of the above methods seem to work for you, then try these methods:
-Try to find a safe computer from where you can can login on your own line accounts like One Drive, iDrive, Google Drive and so on.
-Try to contact your friends, relatives and other people so that they can check if they have some of your important photos or documents just in case you sent them.
-Also, check if some of the files that were encrypted it can be re-downloaded from the web.
-Another clever way to get back some of your files is to find another old computer, a flash drive or even a CD or a DVD where you may have saved your older documents. You might be surprised what will turn up.
-You can also go to your email account to check if you can send any attachments to other people. Usually what is sent the email is saved on your account and you can re-download it. But most importantly, make sure that this is done from a safe computer and make sure to remove the virus first.
More tips you can find on our forums, where you can also asks any questions about your ransomware problem.
How to 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 Prevent SunnyDay 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. In addition, it is also important to keep your passwords secure and to avoid visiting websites or downloading applications from untrusted sources. Finally, ensure you have adequate backup and recovery procedures in place to restore your system to its pre-attack state, should a ransomware attack occur.
Can SunnyDay 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. This means that if a user is infected with ransomware, their data can be stolen and held for ransom. It is important to be aware of this threat and take precautions to protect yourself and your data.
Can Ransomware Affect WiFi?
Yes, ransomware can affect 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 to use them to commit cybercrimes. In some cases, they may even continue to demand additional ransom payments.
Why Is the Ransom Paid in Crypto?
Cryptocurrency is a secure and untraceable form of payment, making it the ideal choice for ransom payments. It is difficult to trace, and the transactions are almost instantaneous. This means it is nearly impossible for authorities to track the payment and recover the money.
Can Ransomware 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, 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.
What is a File Virus and How Do You Remove it?
A "file virus" (ransomware) is a type of malicious software that infects a computer system and encrypts its files and data, preventing the user from accessing them unless they pay a ransom. The virus is usually spread through malicious links, emails, and downloads from untrusted websites. To remove such a virus, it is best to use professional security software to detect and remove it, as well as to restore any encrypted files. It is also important to practice safe computing by avoiding suspicious links, emails, and downloads, and keeping your computer and software up to date with the latest security patches.
Different Types of File Viruses and How to Understand Them?
File viruses are a type of malicious software that can attach themselves to files, such as documents, spreadsheets, and images, and then spread themselves to other computers. The most common types of file viruses are boot sector, macro, file-infecting (ransomware), and multipartite. Each type of virus has its own set of characteristics and behaviors, which can help users identify them and take the necessary steps to protect their data from infection.
What Steps Should You Take to Protect Your Computer from File Viruses?
To protect your computer from file viruses, the first step is to install up-to-date antivirus software. Make sure you keep the software updated and run regular scans to detect and remove any viruses. Additionally, you should be careful when downloading and opening files from unknown sources. If you receive an email with an attachment, be sure to scan the file before opening it. Finally, you should back up all of your important data regularly in case a virus wipes out your files.
How to Identify and Remove Common File Viruses?
Identifying and removing common file viruses can be a tricky process. The first step is to ensure you have an up-to-date anti-virus program installed on your computer. This will help to identify any malicious software on your system. Once identified, it is important to remove the virus as soon as possible.
To do this, you can use a variety of tools such as anti-virus scanners, malware removal programs and system restore points. It is also important to keep your computer up-to-date with the latest security patches to protect your system from future infections.
How to Diagnose and Treat File Viruses?
Ransomware file viruses are a type of malicious software that can cause serious damage to a computer system. To diagnose and treat a ransomware file virus, you must first identify the type of virus and its source. Once identified, you can then use an antivirus program to scan the system and remove the malicious files. Finally, you should create a backup of your system in case the virus returns and update your system's security settings to prevent future infections.
What is the Most Common File Virus?
The most common ransomware virus is called CryptoLocker. It is a malicious software that encrypts files on a computer and demands a ransom in order to unlock them. It is spread through malicious emails, malicious attachments and links, and other malicious websites. CryptoLocker is considered one of the most dangerous ransomware viruses because it can encrypt important documents and data, making them inaccessible unless the ransom is paid.
What Causes File Viruses and How Can They Be Prevented?
File viruses are malicious software that infect computers and encrypt data until a ransom is paid. These viruses are typically spread through malicious emails, websites, and software downloads. To prevent them, it is important to only download software and documents from trusted sources, keep your operating system and applications up to date, and use a reliable anti-malware program.
How to Repair Corrupted Files Due to File Viruses?
Repairing corrupted files due to file viruses is possible, but it requires the use of specialized file recovery or decryptor software. The first step is to scan the system for malicious files and then use the software to repair any affected files. Additionally, it is important to ensure that the system is regularly updated and scanned for any new threats. Finally, it is important to ensure that the system is regularly backed up so that any lost files can be recovered.
How To Avoid File Viruses When Downloading Files From the Internet?
To protect yourself from file viruses when downloading from the web, firstly, only download files from trusted websites or sources. Additionally, use anti-virus software or firewalls to help protect your system from malicious software. Before downloading a file, always make sure to scan it with an anti-malware program to check for any viruses. It is also important to keep your operating system up to date with the latest security patches. Finally, make sure to backup your important files regularly to ensure you can restore them in the event of a ransomware attack.
About the SunnyDay Research
The content we publish on SensorsTechForum.com, this SunnyDay 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 SunnyDay 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.
References
1. How to Recognize Spam Emails with Ransomware
2. How Does Ransomware Encryption Work?
3. How to Decrypt Ransomware Files
4. Ransomware Getting Greedier and Bigger, Attacks Increase by 40%
5. 1 in 5 Americans Victim of Ransomware
Attention! SensorsTechForum strongly recommends that all malware victims should look for assistance only by reputable sources. Many guides out there claim to offer free recovery and decryption for files encrypted by ransomware viruses. Be advised that some of them may only be after your money.
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.