Nemucod ransomware: what it is and how to remove it
Nemucod-AES ransomware is a data-encrypting virus which earned its title by stealthily infiltrating computers, rendering the containing files unreadable with the help of AES-128 and RSA-2048 encryption algorithms, and demanding 0.11471 Bitcoins for their decryption. The criminals choose cryptocurrency as means of payment deliberately.
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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Nemucod ransomware: summary
| Detection names | No Microsoft detection name is known |
|---|---|
| Ransom note | Decrypt.hta; the text is quoted in full below |
| Contact | Not recorded in our earlier report |
| Encrypted file extension | Not recorded in our earlier report |
| Decryptor | No free decryptor is known for this variant; check No More Ransom (nomoreransom.org) for updates |
| Distribution | Not recorded in the old report |
| 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 8 more facts
| Damage | Not recorded in the old report |
|---|---|
| Name | Nemucod |
| Type | File-encrypting ransomware |
| Symptoms | A ransom note left in folders |
| Evidence | 4 write-ups by security sites; details still limited |
| Free decryptor | No free decryptor is known (checked 7 October 2026) |
| First seen | 13 July 2017 |
| Facts checked | 7 October 2026 |
- Note file:
Decrypt.hta
From our report of Jul 2017 · not reviewed since
More from our earlier report on Nemucod
- You can find this instruction in "DECRYPT" file on your desktop.
How Nemucod ransomware behaves
From our report of Jul 2017 · not reviewed since
Nemucod-AES ransomware takes victim's files hostage to demand ransom
Nemucod-AES ransomware is a data-encrypting virus which earned its title by stealthily infiltrating computers, rendering the containing files unreadable with the help of AES-128 and RSA-2048 encryption algorithms, and demanding 0.11471 Bitcoins for their decryption.
The criminals choose cryptocurrency as means of payment deliberately. This method guarantees the anonymity of money transactions and allows the perpetrators to escape prosecution.
That's why you won't get any justice if the hackers disappear with your money after you pay for the data recovery key. This should be a sufficient reason to remove Nemucod-AES from the PC rather than collaborate with the criminals.
Typically to most ransomware, the virus developers drop a ransom note on which they list out all the data recovery conditions and instruct victims where they should purchase and transfer the ransom. Here is a transcript of Decrypt.hta file:
Ransom notes can tell a lot about the ransomware developers, their target audience, and their true intentions. In this case, we have to admit that the note is professionally made and detailed, so the hackers behind it are probably native English speakers and serious enough not to leave spelling or grammatical errors on the note.
The ransomware's target audience is most likely English as well, though it should not stop the virus from infecting users in the European countries, say, Germany or Sweden .
Despite where in the world the virus hits, the first thing infected computer owners should do is perform Nemucod-AES removal.

The Nemucod ransomware note
ATTENTION!
All your documents, photos, databases and other important personal files were encrypted using a combination of strong RSA-2048 and AES-128 algorithms.
The only way to restore your files is to buy decryptor. Please, follow these steps:
1. Create your Bitcoin wallet here:
xxxxs://blockchain.info/wallet/new
2. Buy 0.11471 bitcoins here:
https://localbitcoins.com/buy_bitcoins
3. Send 0.11471 bitcoins to this address:
How to remove Nemucod 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 Nemucod 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
Nemucod encrypts everything it can reach, including drives and shares you connect later. Cut the network first: cable out, or Wi-Fi off from the taskbar.
Then unplug every USB stick and backup disk and pause cloud sync, so the encrypted versions do not replace your online copies. Do not reconnect any of them until the ransomware is removed from the Windows 11 or Windows 10 PC.

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 identify the family
Find the ransom note, usually a
.txt,.htmlor .hta file in every folder or on the desktop, and copy it with one or two encrypted files to a USB stick.From another device, upload them to ID Ransomware or No More Ransom's Crypto Sheriff, which name the family from the note and the file extension. Write down the contact address and your personal ID from the note for the report.
Warning: Never contact the attackers from the infected Windows 11 or Windows 10 PC.

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
For Nemucod, no free decryptor is known (checked 7 October 2026). Search the family name in the No More Ransom decryption tools list and in the free decryptors of Emsisoft, Avast and Kaspersky, because new tools appear years after an attack.
Important: Keep the encrypted files even if nothing works today, and do not pay before every free option is ruled out: payment does not guarantee a working key.
Decryptors run on Windows 11 and Windows 10, but only after the ransomware itself is removed.
Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 4: Remove the ransomware before you restore or decrypt
Restoring or decrypting files while Nemucod still runs lets it encrypt them again. Run a Full scan in Windows Security > Virus & threat protection > Scan options, then the Microsoft Defender Antivirus (offline scan).
If the ransomware blocks Windows Security, start Safe Mode with Networking and scan from there. Some families install a password stealer as well, so let both scans finish on Windows 11 or 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
Open Command Prompt as administrator and run
vssadmin list shadows. If it lists copies dated before the attack, right-click a folder with encrypted files in File Explorer, choose Properties > Previous Versions, and open or restore a version from before that date.ShadowExplorer, a free tool, shows the same copies when the tab is empty or hidden. Most current families delete shadow copies, so an empty list is normal, but the check takes two minutes on Windows 11 or Windows 10.

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
Restore from an external backup, File History or OneDrive's version history, choosing a date before the attack. Connect the backup drive only after the scans are clean, or the ransomware encrypts it too.
If there is no backup, file recovery software can sometimes find the deleted originals, because some ransomware writes an encrypted copy and deletes the original file.
Stop writing to the drive and try recovery on Windows 11 or Windows 10 before new files overwrite the space.
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 Jul 2017 · not reviewed since
Decrypt files encrypted by Nemucod-AES ransomware for free
Victims who have their files compromised by this ransomware can use a free NemucodAES decryptor to restore all data.
The decryptor was successfully created by Emsisoft researchers on July 12th, 2017.
So if your PC was struck by the discussed ransomware and you were hesitating whether to pay up or not, forget these thoughts already. You can restore your files without paying a cent. To find the decryption instructions, look at data recovery section below this post.
The most important thing is to decontaminate the virus and to prevent if from additionally damaging your system. Use the decryptor only after removing the virus from the computer system.

From our report of Jul 2017 · not reviewed since
The ransomware is distributed via fraudulent UPS spam
There are several ways Nemucod-AES ransomware can spread around the web.
A few of the main vectors may be:
Nevertheless, the most salient method of Nemucod-AES distribution campaign are spam emails disguised as UPS service notices. In the two examined samples of spam emails, experts found files called UPS ground-Delivery-005156577.doc.js and UPS ground-Receipt-4424638.doc.js which both obfuscated the malicious JavaScript code by imitating regular Word files.
Please remember this deceptive distribution technique the next time you are on your email. Do not download or, not to mention, open the attachments which may have been sent to you by some unfamiliar senders, because it might be that you are allowing a vicious ransomware on your PC.
- compromised downloads,
- fake software updates,
- deceptive ads,
- exploit kits.
From our report of Jul 2017 · not reviewed since
Suggestions for Nemucod-AES removal
If you have realized that you can no longer access your files anymore and you see a ransom note demanding you to pay money for their recovery, you should wait no longer and start Nemucod-AES removal procedure immediately.
The automatic removal will only take a few minutes, if the ransomware does not attempt to block your security utility and prevent its extermination.
[GI=method-1]Here you will learn how to decontaminate the virus without extra tools.
[GI=method-2]If technique described above won't help run your antivirus, you should try performing the following operation
Rolling back the encrypted files using Windows Previous Versions feature
The guide to Windows Previous Versions feature use is provided below
Employing Shadow Explorer for the data recovery
Shadow Explorer is a method you should definitely try out if the virus has not destroyed the Volume Shadow Copies of your files
Use NemucodAES decryptor
Download NemucodAES decryptor (by Emsisoft) and launch the executable file. Once the User Account Control prompt appears, click Yes. Now you have to be patient, because the decryptor might need a couple hours or so to check your computer system.
The decryption tool will display a message once it finds all files. Click OK and then click Decrypt button in the Emsisoft Decrypter application. Stay patient until it decrypts all of your files.
Once you complete the procedure, delete encrypted file copies from the system.
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 Nemucod 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 ransom notes called Decrypt.hta in every folder.
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 Nemucod ransomware
Should I pay the ransom in Decrypt.hta?
Not before you have tried everything else. Identify the family from Decrypt.hta 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.
When will a decryptor for Nemucod be released?
Nobody can promise a date. When we last checked, on 7 October 2026, no free decryptor is known. Decryptors usually appear after one of three events:
- police seize the attackers' servers and keys
- the authors leak or publish the master keys
- researchers find a mistake in how the ransomware generates keys
Some families got a tool within weeks, others never. Keep the encrypted files and the note on an external drive, check No More Ransom every few months, and follow news about the Nemucod family. A decryptor may need an original file, so keep any unencrypted copies too.
Did Nemucod steal my files or passwords?
We do not know yet. Nothing published so far shows data theft by Nemucod, but the only confirmed sign is ransom notes called Decrypt.hta in every folder, 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.
How did Nemucod get on my computer?
The way Nemucod 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 ransom notes called Decrypt.hta in every folder, 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.
Is Nemucod 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.
What does Decrypt.hta tell me about the ransomware?
Quite a lot. The file name Decrypt.hta, the wording, the contact addresses and the format of the personal ID are typical for each family. Uploading the note together with one encrypted file to ID Ransomware or No More Ransom's Crypto Sheriff usually names the family within seconds.
That name decides your options: some families have free decryptors, some can be partially recovered, and some cannot be decrypted at all. The note's claims about stolen data should be taken seriously but not at face value.
Will my files be deleted if I do not pay in time?
Almost never. Threats to delete files after a countdown are mostly bluff; the encrypted files sit on your disk, and the attackers cannot reach them once the PC is disconnected and cleaned.
A few old families did delete files on a timer while they were still running, which is another reason to remove the ransomware quickly. Copy the encrypted files to an external drive as a safeguard, run the offline scan, and then take your time with recovery and reporting.
How do I open my .docx, .jpg and other files locked by Nemucod?
You cannot open locked files normally while they stay encrypted, and renaming them will not help. Our earlier report did not record the extension that Nemucod adds, so check one locked file name and the ransom note for it.
No free decryptor is known for this variant; check No More Ransom (nomoreransom.org) for updates. Do not rename the files, change the extension or edit them, because that can make recovery harder. Copy the locked files to an external drive before you clean the system, so a decryptor released later still has them.
Will Fortect remove Nemucod?
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 Nemucod, 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
- Norton: Ransomware: 5 dos and don'ts (read October 7, 2026)
- CISA: StopRansomware (read October 7, 2026)
- No More Ransom (read October 7, 2026)
- FTC: How to recognize, remove and avoid malware (read October 7, 2026)
- Microsoft Learn: Microsoft Defender Offline (read October 7, 2026)