Jest ransomware: what it is and how to remove it
Jest ransomware is yet another deadly dangerous cyber infection, which once installed attacks files on a host machine and locks them with a .jest file extension. Although detected on April 1st, 2020, the news about multiple victims all around the world appears not to be an April Fool's joke.
Facts checked October 7, 2026. Removal steps tested on Windows 11 (26H2) and checked against Microsoft's and the browser makers' current documentation. Sections marked as our earlier report are the original text: they describe the threat as it was then and have not been reviewed since. The 2026 status, the removal steps and the questions are current.
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Jest ransomware: summary
| Distribution | Crooks leverage various techniques to distribute malware like Jest. Most of the infections start on Outlook or other e-mail accounts when people open malicious attachments. Furthermore, files may get locked after getting a dangerous infection via a hacked RDP, software cracks, infected hyperlinks, fake software updates, and similar |
|---|---|
| Name | Jest |
| Family | FunFact ransomware |
| Encryption | Jest ransomware uses RSA encryption – an asymmetric cryptographic algorithm, which generates a Private Key to lock personal files on a host PC with a .jest file extension |
| Ransom note | The ransomware changes PC's background image, creates a note; the text is quoted in full below |
| Payment | Criminals behind the ransomware are not too demanding: the ransom they require is equal to 0.3 BTC (more than $2.000) |
| Removal | Scan the PC with security software to find and remove the malware and anything installed with it. Fortect scans Windows for malware and repairs the system files and settings it damaged. Remove it nowTo use the full-featured product, you have to purchase a license for Fortect. The scan is free. |
Show 12 more facts
| Detection names | No Microsoft detection name is known |
|---|---|
| Contact | Not recorded in our earlier report |
| Encrypted file extension | .jest |
| Decryptor | No free decryptor is known for this variant; check No More Ransom (nomoreransom.org) for updates |
| Damage | Not recorded in the old report |
| Type | File-encrypting ransomware |
| Symptoms | Files renamed with a new extension and a ransom note left in folders |
| Evidence | 4 write-ups by security sites; no sample analysed yet |
| Encrypted files | .jest |
| Free decryptor | No free decryptor is known (checked 7 October 2026) |
| First seen | 20 April 2020 |
| Facts checked | 7 October 2026 |
- File extension:
.jest - Note file:
the ransom note
From our report of Apr 2020 · not reviewed since
More from our earlier report on Jest
- The ransomware changes PC's background image, creates a note.ini file on the desktop and scheduled task to display a pop-up called "Unlock manager"
- As soon as you notice ransomware virus on the system, take immediate action to remove it once and for all.
- One and only way to root out the malicious ransomware is to run a full system scan with a professional anti-malware tool while booted in Safe Mode with Networking
- Ransomware initiates multiple compromisation activities against a host machine.
- Consequently, it may encounter errors, BSOD, load problems, and so on.
- To fix such and similar damage, use utility
The Jest ransomware note
What Happened to My Computer?
Your important files are encrypted.
Many of your documents, photos, videos, databases and other files are no longer accessible because they have been encrypted. Maybe you are
busy looking for a way to recover your files, but do not waste your time. Nobody can recover your files without our decryption service.
Can I Recover My Files?
Sure. We guarantee that you can recover all your files safely and easily. But you have not so enough time.
If you want to decrypt all your files, you need to pay.
How Do I Pay?
Payment is accepted in Bitcoin only. For more information, click .
Please check the current price of Bitcoin and buy some bitcoins. For more information, click .
And send the correct amount to the address specified in this window.
After your payment, click .
Once the payment is checked, you can start decrypting your files immediately.
We strongly recommend you to not remove this software, and disable your anti-virus for a while, until you pay and the payment gets processed. If
your anti-virus gets updated and removes this software automatically, it will not be able to recover your files even if you pay!
1. To pay us, you have to use Bitcoin currency. You can easily buy Bitcoins at following sites:
hxxps://cex.io/
hxxps://www.binance.com/
hxxps://www.coinbase.com/
2. After then, if you already have Bitcoins, pay us 0.3 BTC on following our Bitcoin address.
3. Then, press the "Check Payment" button. We will automatically decrypt your files, after bitcoin transfer.
Send 0.3 BTC to;
How to remove Jest ransomware
Tools you'll need
All of these are free except where noted. Download them on a clean device if the infected PC is offline.
- A USB stick: to keep the ransom note, two or three encrypted files and screenshots off the infected PC.
- Microsoft Defender Offline: built into Windows 11 and Windows 10; scans before Windows starts, so running malware cannot hide.
- Microsoft Safety Scanner: a second, portable scanner with current signatures; each download works for 10 days.
- ID Ransomware: identifies the family from the note and one encrypted file and says whether a decryptor exists.
- No More Ransom: the free decryptors from police and security companies; check it again every few months.
- Fortect (optional): scans Windows for malware and repairs the system files and settings it damaged. The free scan is in the box above.
How to remove Jest and get your files back
Work in this order.
Disconnecting comes first, removal comes before any restore, and nothing here asks you to contact the attackers.
Step 1: Disconnect the PC and unplug backup drives
Unplug the network cable or turn off Wi-Fi, and disconnect USB drives, external disks and network shares, so Jest cannot reach more files. Pause OneDrive, Google Drive or Dropbox sync, because synced folders upload the encrypted copies over the good ones.
Leave the PC on but offline while you read the next steps, since a restart can let the ransomware run again. This applies to Windows 11 and Windows 10 alike.
Windows 11: turn off Wi-Fi to take the PC offline. Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 2: Save the ransom note and confirm the family
Your files now end in
.jestand the instructions are inthe ransom note. Save both to a USB stick, a copy of the note and two small encrypted files, before anything else.On another device, check them with ID Ransomware or Crypto Sheriff: the family name decides which decryptor, if any, can help. Keep the note's ID and contact line for your report.
Windows 11: the ransom note and encrypted files to copy for identification. Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 3: Check for a free decryptor
Our last check found that for Jest, no free decryptor is known (checked 7 October 2026). Look again yourself in the No More Ransom list and the free decryptor pages of Emsisoft, Avast and Kaspersky, which add new families every year.
A decryptor needs the ransomware gone first, or it encrypts the files again. Keep at least one copy of the encrypted files on an external drive, even if no tool works yet.
Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 4: Remove the ransomware before you restore or decrypt
Removing Jest does not bring the files back, but it has to come first. Start with Defender's Full scan, then the offline scan from the same Scan options page, which checks the disk before Windows loads.
If the scan cannot start, use Safe Mode with Networking. Delete the ransom notes only after you have saved a copy, because removal tools sometimes leave them behind on Windows 11 and Windows 10.
Windows 11: Windows Security > Virus & threat protection > Scan options. Full procedure with screenshots: Run a Microsoft Defender Offline scan
Step 5: Look for shadow copies of the files
Windows keeps shadow copies for restore points and backups, and some ransomware fails to delete them.
vssadmin list shadowsin an administrator Command Prompt tells you at once whether any exist.If they do, right-click the folder that held your files, open Properties > Previous Versions, select a version from before the attack, and click Open to check it before you Restore or copy the files out. Windows 11 and Windows 10 both have the tab.
Windows 11: vssadmin list shadows shows whether shadow copies exist. Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 6: Restore the files from a backup or recover deleted originals
A backup made before the attack is the surest way back. Connect it only once the PC is clean, then restore from File History, Windows Backup, OneDrive's Restore your OneDrive or your own external copies.
Without a backup, try file recovery: the originals that Jest deleted may still be on the disk until something overwrites them. Install nothing new on the drive you want to recover from on the Windows 11 or Windows 10 PC.
Full procedure with screenshots: Recover deleted files (Recycle Bin, backups, OneDrive) On uGetFix
Instructions for each browser and system
The detailed steps for every browser and system this guide covers. Open the one you use.
Manual removal using Safe Mode
Important! →
Manual removal guide might be too complicated for regular computer users. It requires advanced IT knowledge to be performed correctly (if vital system files are removed or damaged, it might result in full Windows compromise), and it also might take hours to complete. Therefore, we highly advise using the automatic method provided above instead.
Step 1. Access Safe Mode with Networking
Manual malware removal should be best performed in the Safe Mode environment.
Windows 7 / Vista / XP
- Click Start > Shutdown > Restart > OK.
- When your computer becomes active, start pressing F8 button (if that does not work, try F2, F12, Del, etc. - it all depends on your motherboard model) multiple times until you see the Advanced Boot Options window.
- Select Safe Mode with Networking from the list.
Windows 10 / Windows 8
- Right-click on Start button and select Settings.
- Scroll down to pick Update & Security.
- On the left side of the window, pick Recovery.
- Now scroll down to find Advanced Startup section.
- Click Restart now.
- Select Troubleshoot.
- Go to Advanced options.
- Select Startup Settings.
- Press Restart.
- Now press 5 or click 5) Enable Safe Mode with Networking.
Step 2. Shut down suspicious processes
Windows Task Manager is a useful tool that shows all the processes running in the background. If malware is running a process, you need to shut it down:
- Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
- Click on More details.
- Scroll down to Background processes section, and look for anything suspicious.
- Right-click and select Open file location.
- Go back to the process, right-click and pick End Task.
- Delete the contents of the malicious folder.
Step 3. Check program Startup
- Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
- Go to Startup tab.
- Right-click on the suspicious program and pick Disable.
Step 4. Delete virus files
Malware-related files can be found in various places within your computer. Here are instructions that could help you find them:
- Type in Disk Cleanup in Windows search and press Enter.
- Select the drive you want to clean (C: is your main drive by default and is likely to be the one that has malicious files in).
- Scroll through the Files to delete list and select the following:
Temporary Internet Files
Downloads
Recycle Bin
Temporary files - Pick Clean up system files.
- You can also look for other malicious files hidden in the following folders (type these entries in Windows Search and press Enter):
%AppData%
%LocalAppData%
%ProgramData%
%WinDir%
After you are finished, reboot the PC in normal mode.
From our report of Apr 2020 · not reviewed since
Jest ransomware takes advantage of unprotected RDP servers to attack host PCs and demand Bitcoins in exchange for a decryption key
Jest ransomware is yet another deadly dangerous cyber infection, which once installed attacks files on a host machine and locks them with a .jest file extension.
Although detected on April 1st, 2020, the news about multiple victims all around the world appears not to be an April Fool's joke. Stemming from FunFact ransomware, the Jest virus actively spreads as a .zip and .exe spam attachment, malicious downloads of pirated software, and unprotected RDP servers.
Upon infiltration, it compromises the system's boot files, registry entries, and activates RSA cipher to encrypt files, such as pictures, videos, documents, databases, stored on a host machine. Subsequently, each locked file gets an appendix .jest and cannot be renamed, opened, moved or otherwise used. The victim is informed about an attack via a ransom note called "Note.ini," which instructs a victim to transfer 0.3 BTC (currently over $2,000).
The criminals behind Jest ransomware seek to earn 0.3 BTC, which is not a huge ransom if compared to crypto-malware like RagnarLocker. Anyway, paying more than $2,000 for criminals is a huge loss, especially for files and data that belongs to you. To "facilitate" the process of payment, criminals provide links to the Bitcoin purchase websites and explanation on how and where the transfer has to be done.
Once Jest ransomware payload is launched, the virus drops an executable file, which starts an attack in the background, and later Windows Registry to activate malicious registry keys. Consequently, the virus ensures that it will be booted along with the PC's activation.
The malicious executable file, at the same time, launches the encryption software and targets personal files stored on the machine. Finally, when the files are encrypted by .jest file extension and other background processes are done, the ransomware replaces desktop's background image "YOUR FILES HAVE BEEN ENCRYPTED" and generates a scheduled popup window Unlock Manager.
The later, just like a txt form ransom note, provides instructions on how to pay the redeem for a personal decryption key. Besides, it displays a countdown clock, which gives the victim 24 hours to contact with the criminals.
If you are under attack at the moment, you have two options, i.e. to purchase Bitcoins and send them to criminals or remove Jest ransomware and try to recover your files using alternative solutions.
Windows Volume Shadow Copies won't help in this case, as the ransomware is programmed to remove all the copies. Even more, if you have the backups of the most valuable files, do not even consider paying the ransom at all.
One may think that ransomware removal is a task for tech-savvy ones. In fact, the success of the Jest removal depends much on the AV software that you are using. According to VirusTotal , 56 out of 71 AV engines are capable of detecting and removing this threat. Therefore, if you have a professional Antivirus program, launch its scanner and wait for it to report a successful removal of Win32:
- Malware-gen
- Gen:NN.ZevbaF.34106.@pKfaOo2H3oO
- Win32/Filecoder.OBM
- Trojan.Win32.DelShad.cxv
- Gen:Heur.Ransom.Imps.1
- similar malware
From our report of Apr 2020 · not reviewed since
Typical ways of ransomware propagation
IT experts from NoVirus.uk and other partners do not exaggerate admonishing how dangerous it is to open email messages from unrecognized senders.
Email spam campaigns are extremely common, so if your email address has been leaked many times, you may receive tens of dangerous messages imitating DHL, FedEx, Federal Income Tax Treatment, or other authorities. More elaborate scam campaigns can disguise under chief executive personas' from Red Cross, Facebook, and similar.
Usually, these messages are well-prepared. However, some grammar, typo mistakes or formatting are left suspicious. Therefore, do not open the attachments if you were not waiting for a specific document from a known person.
If you have any doubts, reply to the sender and double-check if the attachment is safe to open. The bot will never answer your question.
Aside from spam, ransomware can be deployed via software cracks on peer-to-peer networks, hacked RDP servers, malicious ad campaigns, software updates, and similar media. Ransomware can hardly be injected into well-protected websites or reputable downloads, though there may be exclusions.
Therefore, you must not visit dangerous websites, avoid downloading software recklessly and stay away from intriguing ads. Besides, protect your machine with a reliable AV engine that has an in-built real-time protection feature.
From our report of Apr 2020 · not reviewed since
Comprehensive Jest ransomware removal instructions and data recovery tips
Do not wait long considering pay the ransom or not.
The longer you hesitate, the more files you may lose. Once you detect your files encrypted, launch an antivirus scanner and remove Jest ransomware immediately.
In most of the cases, ransomware viruses block AV engines. That's a common practice, so don't fall for panic. Jest removal will definitely be successful if you boot Windows into Safe Mode with Networking. After that, launch or and let the program do its job.
Finally, the corrupted files should still have the .jest extension. If you have backups, then remove the useless files and use the copies. If there are no backups, we will give you a couple of useful tips on how to recover files encrypted by .jest. If neither of them helps, you may need to contact a professional IT-expert to crack the encryption algorithm down.
[GI=method-1]Ransomware virus runs multiple malicious processes and can severely damage the Windows system. To protect your PC from a full crash, delete the package of the virus by running the system into Safe Mode and launching the AV scanner:
[GI=method-2]All malicious aftereffects, except encrypted files, can be returned to the state before ransomware attack by restoring the system to the previous version:
Since the program is easy to use, you can give it a try.
take advantage of Windows Previous Version feature to recover files locked by Jest ransomware
There is no Jest ransomware decryption software yet
Report it and recover your files
Report it
Report the attack even if you do not expect the files back: insurers and banks ask for the report number, and police use the contacts in the note to link cases.
- United States
- FBI IC3 · FTC ReportFraud
- United Kingdom
- Report Fraud (formerly Action Fraud) · NCSC
- Australia
- ReportCyber (ASD)
- EU countries
- Europol: national reporting sites
Give the victim ID, the note and the date the files were encrypted. A business that holds personal data may also have to notify its data protection authority, in the EU within 72 hours.
Backups: the 3-2-1 rule
Keep three copies of files that matter, on two kinds of storage, with one copy offline or off-site.
A disk that stays plugged in is reached by malware like Jest together with the PC; one you connect only for the backup is not.
On Windows 11, File History keeps versions on an external drive, and OneDrive keeps earlier versions of synced files. Before restoring anything, make sure the PC no longer shows files that end in .jest and no longer open.
Setting it up step by step: 3-2-1 backups on Windows 11 and 10.
Choose a proper web browser and improve your safety with a VPN tool
Online spying has got momentum in recent years and people are getting more and more interested in how to protect their privacy online.
One of the basic means to add a layer of security - choose the most private and secure web browser. Although web browsers can't grant full privacy protection and security, some of them are much better at sandboxing, HTTPS upgrading, active content blocking, tracking blocking, phishing protection, and similar privacy-oriented features.
However, if you want true anonymity, we suggest you employ a powerful VPN - it can encrypt all the traffic that comes and goes out of your computer, preventing tracking completely.
Lost your files? Use data recovery software
While some files located on any computer are replaceable or useless, others can be extremely valuable.
Family photos, work documents, school projects - these are types of files that we don't want to lose. Unfortunately, there are many ways how unexpected data loss can occur:
- power cuts
- Blue Screen of Death errors
- hardware failures
- crypto-malware attack
- even accidental deletion
To ensure that all the files remain intact, you should prepare regular data backups. You can choose cloud-based or physical copies you could restore from later in case of a disaster. If your backups were lost as well or you never bothered to prepare any, can be your only hope to retrieve your invaluable files.
Questions about Jest ransomware
Is there a decryptor for .jest files?
That depends on the family behind the .jest extension, which this guide cannot confirm yet from the reports alone. Check No More Ransom and ID Ransomware with your ransom note and one encrypted file; they list families with free tools.
If none exists today, keep the encrypted files and a copy of the note on a separate drive, because decryptors are sometimes published months later after flaws are found or servers are seized. Never buy a decryptor from a website that is not the security company that made it.
Should I pay the ransom in the ransom note?
Not before you have tried everything else. Identify the family from the ransom note and one encrypted file, check No More Ransom for a free decryptor, and look for clean copies in OneDrive, backups and Previous Versions.
Paying funds further attacks, may be illegal if the group is sanctioned, and is no promise of a working key: many victims get partial or broken decryption. If you consider paying for business-critical data, involve the police and a professional incident responder first, and never pay through intermediaries who promise their own decryption.
How do I open .jest files?
You cannot open them by renaming or by choosing another program. The .jest ending shows that Jest encrypted the content, and only the matching key can reverse it. Renaming a file back to .docx or .jpg changes nothing except the icon, and it can confuse a future decryptor, so leave the names as they are.
To get the content back, use a backup, an unencrypted copy elsewhere, or a decryptor listed on No More Ransom if one exists for Jest. Store the encrypted files on an external disk until then.
How did Jest get on my computer?
The way Jest spreads has not been documented yet, so look at your own recent activity. On home PCs, ransomware most often comes with cracked programs, game cheats, key generators and fake updates, or with an e-mail attachment that was opened. On business networks, attackers usually log in through Remote Desktop with a stolen or guessed password.
Think back to what was downloaded or installed in the days before files that end in .jest and no longer open, and check the Downloads folder and Installed apps sorted by date. Keep anything suspicious for your report, but do not run it again.
Can a data-recovery company decrypt my files for a fee?
Only if a decryptor already exists or the company pays the attackers for you. Some "ransomware recovery" services advertise that they can decrypt families with no known flaw; in practice they negotiate with the attackers and add their own fee. Others use the same free tools listed on No More Ransom.
Before you hire anyone, ask in writing how they will recover the files, whether they will contact the attackers and what happens if they fail. A legitimate service answers clearly. If a free decryptor exists for your family, you can run it yourself.
Did Jest steal my files or passwords?
We do not know yet. Nothing published so far shows data theft by Jest, but the only confirmed sign is files that end in .jest and no longer open, which says nothing about what happened before. Many current ransomware attacks copy files or run a password stealer first, so it is wise to act as if they did.
From a clean device, change the passwords that were saved in the browsers on this PC, starting with e-mail and banking, sign out of all sessions and turn on two-step verification. Watch bank statements and account activity for the next few weeks.
Is Jest the same as other ransomware with a similar name?
Not necessarily. Ransomware names come from the file extension, the note or a word in the code, so unrelated families often end up with similar names, and one family can appear under several names. The difference matters: a decryptor or advice for one family does not fit another and can damage files.
Compare the ending added to your files and the exact name of the note with the summary table at the top of this guide, then upload the note and one encrypted file to ID Ransomware from a clean device. If the result names another family, follow the guide for that family instead.
Can I delete the ransom note?
Yes, the note itself is harmless text and deleting it does not affect your files. Keep at least one copy first, outside the infected PC. the ransom note contains your personal ID and the attackers' contact details, which identification services use to tell which family encrypted your files, and which a decryptor may need later.
Police reports also ask for it. Once you have saved a copy, you can remove the notes from every folder after the ransomware program has been removed and your files are restored or backed up.
My files got .jest overnight. What happened?
Ransomware often runs at night or when the PC is idle, so the encryption finishes before anyone notices. It usually entered earlier through a cracked program, a fake installer, an e-mail attachment or remote desktop with a weak password.
The .jest extension marks every file it reached. Start by disconnecting the PC from the network, then identify the family from the ransom note and one encrypted file, check for a decryptor, and look for copies in backups and OneDrive before you consider anything else.
Will Fortect remove Jest?
Fortect scans Windows for malware and unwanted programs and repairs the system files and settings they change, and its free scan shows what it finds on your PC before you decide anything.
For Jest, follow the plan above as well: the browser steps take back permissions and settings that no scanner treats as a threat, and uninstalling the program that brought it removes the source.
Run Microsoft Defender's full scan and, if anything was found, its offline scan as a second opinion. If the symptoms are gone after the plan and both scans are clean, there is nothing more to do.
Sources
- Microsoft: Volume Shadow Copy Service (read October 7, 2026)
- VirusTotal: Virus Total analysis (read October 7, 2026)
- Fortinet: State of Email Security in 2020: More Spam, Malware, Phishing & Ransomware Ahead (read October 7, 2026)
- CISA: StopRansomware (read October 7, 2026)
- No More Ransom (read October 7, 2026)