LambdaLocker ransomware virus: what it is and how to remove it
LambdaLocker is a virus written in Python that functions as a file-encrypting tool. Cybercriminals use to extort computer users.
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.
Automatic
Get a free scan and check if your PC is infected.
Fortect finds malware, unwanted programs and the Windows damage they leave behind, and repairs it in one pass.
Before restoring files, a full scan can confirm the program that left READ_IT.hTmL is no longer on the PC.
Do it yourself · free Remove LambdaLocker ransomware virus yourself 6 steps, about 18 minutes, no software needed.
Start the steps
LambdaLocker ransomware virus: summary
| Detection names | No Microsoft detection name is known |
|---|---|
| Ransom note | READ_IT.hTmL; the text of the note is not in our records |
| Contact | atlantis.cf@yandex.com, lambdasquad.hl@yandex.com |
| 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 9 more facts
| Damage | Not recorded in the old report |
|---|---|
| Name | LambdaLocker ransomware virus |
| Type | File-encrypting ransomware |
| Symptoms | A ransom note left in folders |
| Evidence | 8 write-ups by security sites; details still limited |
| Attacker contacts | atlantis.cf@yandex.com |
| Free decryptor | No free decryptor is known (checked 7 October 2026) |
| First seen | 17 August 2017 |
| Facts checked | 7 October 2026 |
- Note file:
READ_IT.hTmL - Contact:
atlantis.cf@yandex.com
From our report of Aug 2017 · not reviewed since
More from our earlier report on LambdaLocker ransomware virus
- Avast has created an efficient data decryption tool that works on files with .MyChemicalRomance4EVER file extensions.
The LambdaLocker ransomware virus ransom note
The note is called READ_IT.hTmL.
We did not record the full text of the ransom note in our report.
How to remove LambdaLocker ransomware virus
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 LambdaLocker ransomware virus 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
LambdaLocker ransomware virus 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 LambdaLocker ransomware virus, 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 LambdaLocker ransomware virus 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 Aug 2017 · not reviewed since
LambdaLocker virus is finally defeated - decrypt your files now
LambdaLocker is a virus written in Python that functions as a file-encrypting tool.
Cybercriminals use to extort computer users. The latest version presents the ransom demand in UNLOCK_guiDE.tXT file. Interestingly, the author of this malware seems to be a fan of American band rock band as it appends .MyChemicalRomance4EVER file extension and presents atlantis.cf@yandex.com email address for the contact purposes.
The malware authors are quite greedy as they demand 6000 and 700 yuan ($1040) in exchange of the data.
The first versions of Lambda Locker have been detected on January 2017, but after half a year, the developers attempt to revive the threat again. Speaking of the original version, it functions as an ordinary crypto-malware targeting Windows OS and employing AES-256 encryption method to block the most valuable cyber possessions – personal data. In particular, such viruses infiltrate computers by stealth and encrypt files with asymmetrical AES and RSA algorithms .
This variation specifically targeted Chinese-speaking countries . In the ransom note, READ_IT.hTmL, the perpetrators demand 0.5 bitcoins which at the amount amounts to $1352.40. This version marks the files with .lambda_l0cked file extension. The virus suggests writing to lambdasquad.hl@yandex.com after paying the ransom.
The data decryption key is stored on a remote server, where the victims would not be able to reach it and use it to decrypt their files. Then comes the time for the LambdaLock creators to offer their solution to the problem.
The victim is offered to redeem the files by transferring some Bitcoins to an indicated Bitcoin wallet address . Frankly, the victims are proposed to pay for what is already theirs. That's what earns this parasite a name of a ransomware virus.
If you are ever in a situation where you are being coaxed into collaborating with anonymous hackers, or more importantly, sending them money for questionable tools, do not lose your cool and remove LambdaLocker from your computer. or will be of assistance in this process.
Of course, you should keep in mind that this will not help recover the files but merely delete the virus and its components from the computer. Nevertheless, when the virus is fully eliminated from the computer, you can then employ alternative data recovery techniques to restore some of your important files without a risk of losing your money.
Frankly, the victims are proposed to pay for what is already theirs. That's what earns this parasite a name of a ransomware virus. If you are ever in a situation where you are being coaxed into collaborating with anonymous hackers, or more importantly, sending them money for questionable tools, do not lose your cool and remove LambdaLocker from your computer.
Of course, you should keep in mind that this will not help recover the files but merely delete the virus and its components from the computer. Nevertheless, when the virus is fully eliminated from the computer, you can then employ alternative data recovery techniques to restore some of your important files without a risk of losing your money.
Like most viruses of the kind, Lambda Locker crypto-ransomware has specific features that make it unique and help us to differentiate it from other ransomware. For instance, from the .lambda_l0cked extension that it appends to the infected files you can already tell what kind of virus has infected your computer and start taking certain steps towards its removal.
Besides, you will also notice the READ_IT.hTmL file that will be added to your desktop and every other computer folder that contains encrypted documents. This file is a ransom note which will try to convince users to pay the 0.5 Bitcoin ransom for the data decryption.
It is interesting that the note is written in English and Chinese, so we can presume that the ransomware is specifically targeted toward English and Chinese-speaking countries.
Nevertheless, that does not limit the parasite from spreading to other parts of the world. So, no matter where you live, you might one day find that your pictures, audio/video files, Office documents, and archives have been encrypted and that you are in need of a good LambdaLocker removal advice. In such a case, we suggest continue reading the article and learn more about the virus extermination techniques.
Good news: Victims of Lambda Locker ransomware can now recover their files for free. Please follow the instructions we provided (you can find them below the virus removal guide) and restore your files without paying a cent.
From our report of Aug 2017 · not reviewed since
New ransomware versions spotted
.MyChemicalRomance4EVER file extension virus seems to be programmed in Python programming language.
The ransom message is fully provided in Chinese. In comparison with the original version, the developers are quite greedy they demand 6000 ($885) yuan in exchange for the files. In case a victim fails to transfer the files within the specified amount of time, the amount will increase up to 1000 dollars.
In case affected users encounter any difficulties, they should contact the perpetrators via atlantis.cf@yandex.com. They also provide instructions how to purchase bitcoins. Luckily, there is no need to comply with the demands as the malware is decryptable.
The virtual threat is detected as W32/Trojan.QNSF-9385 or Generic.Ransom.LambdaLocker.7965CD21 (B). It might disguise under VortexVPN.vir.DNvir file. Be vigilant while you are downloading new applications. Do not install programs which are released by "unknown" publishers.
From our report of Aug 2017 · not reviewed since
Distribution tricks that help the virus proliferate
We have already mentioned that LambdaLocker is a typical ransomware example and what we mean that it all respects, including its distribution as well.
This means that the virus may spread via exploit kits, fake software updates or bundled inside software packages.
Besides, the virus may also be delivered to your email inbox by the malicious spam campaigns . That is why we suggest being careful with the emails you open and the attachments you download to your computer. You never know whether Lambda Locker is not hidden under some legitimate-looking flight confirmation, speeding ticket or even a simple picture .
From our report of Aug 2017 · not reviewed since
Remove LambdaLocker like a professional
When talking about LambdaLocker removal, we should point out that it is not an easy task.
Ransomware viruses are usually designed to fight back and try to stay on the infected computers by all means possible. Thus, even automatic malware elimination tools might sometimes find it complicated to tackle the viruses properly, not to mention manual removal.
One of the major obstacles that anti-ransomware programs face is the blocking of the system scan. When the antivirus cannot scan the system, it cannot locate files of the parasite. Thus, it cannot remove LambdaLocker virus from the computer. Reboot the system into Safe Mode to get rid of the infection.
[GI=method-1]In case Lambda Locker blocks your antivirus, follow the instructions provided below.
[GI=method-2]LambdaLocker can be decontaminated manually using the instructions provided below.
Currently, there is no way to decrypt LambdaLocker encrypted files for free. And the experts might take some time to come up with a free decryption tool as well. Thus, if you are looking for a quick solution, we suggest looking at the alternative data recovery techniques below.
The tool will execute all the decryption steps automatically and attempt to recover as much of your data as possible. Instructions how to use this program are given here:
Try out Windows Previous Versions feature:
Windows Previous Versions feature may help you recover files. There is one condition, though. For this method to work, the System Restore function has to be enabled on the computer. If it hasn't been activated before the virus attack, the Windows Previous Versions feature method will probably be of little use.
Recover your files with the help of ShadowExplorer
ShadowExplorer is the final option we can suggest for the data recovery. Nevertheless, if the virus deletes Volume Shadow Copies of the encrypted files, the recovery will most likely be unsuccessful. However, you can always give it a try. Here is what you do:
Though some of virus versions do not seem to have decrypters yet, you can decrypt files affected by .MyChemicalRomance4EVER malware variation. Before you do, check the above guide how to eliminate the infection.
You can download LambdaLocker fix from here. Follow the instructions provided by the tool to decrypt your files.
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.
Protect the files you restore
Restore only after the scans are clean and the PC no longer shows ransom notes called READ_IT.hTmL in every folder; otherwise the restored copies can be damaged again.
Then build a backup that survives the next infection:
- one copy in the cloud with version history
- one on an external drive that is disconnected between backups
- the working copy on the PC
Version history matters because a backup that syncs damaged files overwrites the good ones.
How to do this with the tools built into Windows: the 3-2-1 backup rule on Windows.
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 LambdaLocker ransomware virus
When will a decryptor for LambdaLocker ransomware virus 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 LambdaLocker ransomware virus family. A decryptor may need an original file, so keep any unencrypted copies too.
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.
Should I pay the ransom?
We advise against it, and so do the FBI, Europol and national cyber agencies. Payment does not guarantee a working tool: some attackers never reply, some tools damage files, and some variants have no decryptor at all. Paying also funds further attacks and can make you a target again.
Before considering payment, try every recovery option in this guide and report the attack. Companies must involve their legal adviser and insurer, because payments to sanctioned groups can be illegal. If files are truly irreplaceable, store the encrypted copies and wait; decryptors sometimes appear later.
How did LambdaLocker ransomware virus get on my computer?
The way LambdaLocker ransomware virus 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 READ_IT.hTmL 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.
Did LambdaLocker ransomware virus steal my files or passwords?
We do not know yet. Nothing published so far shows data theft by LambdaLocker ransomware virus, but the only confirmed sign is ransom notes called READ_IT.hTmL 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.
Is LambdaLocker ransomware virus 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 READ_IT.hTmL tell me about the ransomware?
Quite a lot. The file name READ_IT.hTmL, 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.
Is READ_IT.hTmL from real ransomware or a bluff?
Look at your files rather than the note. If documents and photos have a new extension and will not open, the encryption is real. If files open normally, or only a few were renamed, the note may come from fake ransomware or extortion-only malware that claims more than it did.
Some wipers also leave notes like READ_IT.hTmL while destroying data with no way back. Identification services help here too: they recognise the note and tell you whether the family is known to encrypt, to bluff, or to wipe.
How do I open my .docx, .jpg and other files locked by LambdaLocker?
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 LambdaLocker 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 LambdaLocker ransomware virus?
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 LambdaLocker ransomware virus, 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
- KnowBe4 website: A short history and evolution of ransomware (read October 7, 2026)
- ZDNet: How Bitcoin helped fuel an explosion in ransomware attacks (read October 7, 2026)
- Twitter: New version of LambdaLocker Python ransomware (read October 7, 2026)
- CISA: StopRansomware (read October 7, 2026)
- No More Ransom (read October 7, 2026)