Babuk Locker ransomware virus - removal and decryption options

What kind of malware is Babuk Locker?

Babuk Locker is ransomware that creates the "How To Restore Your Files.txt" file (ransom message) in all folders that contain encrypted files and renames the files by appending the ".__NIST_K571__" extension. For example, "1.jpg" is renamed to "1.jpg.__NIST_K571__", "2.jpg" to "2.jpg.__NIST_K571__", and so on.

Babuk Locker ransomware may also append ".babuk" or ".babuk2" extension. Babuk Locker uses SHA256 hashing, ChaCha8 encryption, and the ECDH key generation and algorithm to secure its keys and encrypt files.

Research shows that cyber criminals behind Babuk Locker target mainly companies, however, they might also target regular users. Note that this ransomware was discovered by Glacius_.

Screenshot of files encrypted by Babuk Locker (".__NIST_K571__" extension):

Ransom note overview

Victims of Babuk Locker are informed that they cannot restore (decrypt) their files without decryption software that can be purchased only from the developers of this ransomware. To get instructions about how to pay for the software, victims are instructed to contact developers via chat on the provided Tor website.

Unfortunately, there are no third party tools that can decrypt files that are encrypted by Babuk Locker. Paying the ransom does not guarantee that ransomware developers will provide any decryption tools. Therefore, the only way to recover files without losing money and risk being scammed is to restore them from a backup.

Further encryption of any unaffected files can be prevented by uninstalling the ransomware, however, already compromised files remain encrypted even after removal of the rogue software.

Note that Babuk Locker encrypts files and attempts to delete shadow copies before (and after) encryption, encrypts remote drives, uses the Windows Restart Manager to end any process that might prevent it from encrypting files. Some examples of processes that it terminates are excel.exe, notepad.exe, sql.exe, firefox.exe, outlook.exe, ocssd.exe, dbsnmp.exe, and isqlplussvc.exe.

Ransomware in general

Main differences between ransomware programs are size of ransom and cryptographic algorithm used for file encryption.

Victims cannot decrypt files without tools held only by ransomware developers, unless in rare cases ransomware is not finished (contains bugs/flaws). Therefore, maintain backups on remote servers and/or unplugged storage devices (e.g., Cloud).

More ransomware examples are Ziggy, WormLocker and Qlkm.

How did ransomware infect my computer?

Typically, ransomware and other malware is distributed through malspam campaigns, fake software updating tools, untrusted download sources, unofficial (third party) software activation tools and Trojans. Users infect computers with malware when they open malicious files that they receive via email.

These emails often contain malicious attachments or websites designed to download dangerous files. In most cases, cyber criminals send emails that have Microsoft Office documents, archive files (ZIP, RAR), PDF documents, JavaScript files, and executable files such as .exe attached to them. Fake software updating tools do not update or fix any installed software - they simply install malware instead.

They can also infect systems by exploiting bugs/flaws of outdated software. Examples of dubious file/software download channels are Peer-to-Peer networks such as torrent clients, eMule, various free file hosting sites and freeware download websites.

Users infect computers through these channels when they download and execute malicious files, which are often disguised as legitimate and regular. Software 'cracking' tools supposedly activate licensed software free of charge (illegally), however, rather than activating anything, they often install malicious programs.

Trojans are rogue programs that, if installed, install other malware (causing chain infections).

How to protect yourself from ransomware infections

Download software and files from official websites and via direct links. It is not safe to use torrent clients, eMule (or other Peer-to-Peer networks), third party downloaders, unofficial websites or other sources of this kind.

Avoid third party installers. Check "Advanced", "Custom" and other settings, and decline offers to download or install unwanted software. Do not click ads that are displayed on dubious websites, since they can open other untrusted websites or even cause unwanted downloads and installations.

Remove any unwanted, suspicious applications (extensions, add-ons, and plug-ins) that are installed on the browser. The same should be applied to programs of this kind that are installed on the operating system.

Regularly scan your computer with reputable antivirus or anti-spyware software and keep this software up to date.

If your computer is already infected with Babuk Locker, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate this ransomware.

Screenshot of the "How To Restore Your Files.txt" file:

Text in the "How To Restore Your Files.txt" file:

----------- [ Hello! ] ------------->

       ****BY BABUK LOCKER****

What happend?
----------------------------------------------
Your computers and servers are encrypted, backups are deleted from your network and copied. We use strong encryption algorithms, so you cannot decrypt your data.
But you can restore everything by purchasing a special program from us - a universal decoder. This program will restore your entire network.
Follow our instructions below and you will recover all your data.
If you continue to ignore this for a long time, we will start reporting the hack to mainstream media and posting your data to the dark web.

What guarantees?
----------------------------------------------
We value our reputation. If we do not do our work and liabilities, nobody will pay us. This is not in our interests.
All our decryption software is perfectly tested and will decrypt your data. We will also provide support in case of problems.
We guarantee to decrypt one file for free. Go to the site and contact us.

How to contact us?
----------------------------------------------
Using TOR Browser ( hxxps://www.torproject.org/download/ ):
hxxp://babukq4e2p4wu4iq.onion/login.php?id=8M60J4vCbbkKgM6QnA07E9qpkn0Qk7

!!! DANGER !!!
DO NOT MODIFY or try to RECOVER any files yourself. We WILL NOT be able to RESTORE them.
!!! DANGER !!

Screenshot of the Tor website that victims are instructed to use to communicate with Babuk Locker's developers:

Update 14 January 2021 - Criminals have recently released an updated variant of Babuk Locker ransomware, which uses a different file extension: ".babyk". The ransom message, however, remains identical.

Screenshot of files encrypted by this Babuk Locker ransomware variant (".babyk" extension):

Appearance of a ransom message dropped by Babuk Locker ransomware, which appends the ".babyk" extension (GIF):

Text presented within:

############## [ babuk ransomware greetings you ] ##############

Introduction
----------------------------------------------
Congratulations! If you see this note, your company've been randomly chosen for security audit and your company haven't passed it.
Unfortunately your servers are encrypted, backups are encrtypted too or deleted.
Our enctyption algorythms are strong and it's impossible to decrypt your stuff without our help.
Only one method to restore all your network and systems is - to buy our universal decryption software.
Follow simple steps that discribed down below and your data will be saved.
In case you ignore this situation, the consequences could me much serious, than you can imagine.

Guarantees
----------------------------------------------
The hack and system encryption wasn't compromised by your competitors or any other 3rd party, this is just and only our initiative and only thing we interested is profit.
Accurding the previous sentence We are very much value of our reputation. If we do not do our work and liabilities, nobody will pay us. This is not in our interests.
All our decryption software is perfectly tested and will decrypt your data. We guarantee full support and help through the all decryption process.
As the proof of our abilities and honesty, we can decrypt few small files for free, check the link provided and ask any questions.

Data leakage
----------------------------------------------
We have copied some quantity of data from your servers.
Check those proofs and estimate the seriousness of consequences which can occur in case you ignore us: hxxp://wavbeudogz6byhnardd2lkp2jafims3j7tj6k6qnywchn2csngvtffqd.onion/blog/c9daf42fcfa6aca8432ecb7ffeff7f5e4e75f4ddd75f428c629bf6aa6a108a08/
This link is private and only you can see it.
Use tor browser to open link.
Ignoring the interaction with us brings you the publishing your data in our public blog hxxp://wavbeudogz6byhnardd2lkp2jafims3j7tj6k6qnywchn2csngvtffqd.onion/

Contact
----------------------------------------------

1) Download tor browser: hxxps://www.torproject.org/download/
2) Open it
3) Follow this link in tor browser: hxxp://tsu2dpiiv4zjzfyq73eibemit2qyrimbbb6lhpm6n5ihgallom5lhdyd.onion/3eb91fac85bb0db5dde432443e998a3863f0f1c76e3449319178e6b78f5d3f44

* 6 simple steps do minimize harm from ransomware.
----------------------------------------------
Thousands of companies around the world are struggling on ransomware these days, and the most of companies are making the same mistakes again and again. Let’s figure out how to minimize harm and do not be a dumb and pathetic donkey which will make fun for journalists and so on..
1. If you see small fella malicious .exe file never load it to virustotal.com or any other virus researching website.
Otherwise the info about the hack is not a secret anymore. The fact that your company is under ransomware attack is already known by filthy predators data security agents who will post in their pity twitters the fresh known news “OMG ANOTHER RANSOMWARE NOW IT’S “Your company name LLC!!!!! We are all gonna die aaaaaa halp”

2. No any public announcements about the hack or data leakage. And do not applicate to law enforcement.
If you commit this actions, more serious consequences can occur and you pay much more than a ransom amount. Law structures like GDPR in this case can oblige you to pay huge fine.

3. As soon as you see your network compromised, follow the link inside any note and follow instructions.

4. Calm your employees.
Explain them that this is a drill. And you test your network security systems.

5. If you decide to hire the data recovery company, obligate them to do not inform anyone and any third party about details of the attack.
We strongly do not recommend to cooperate with data recovery company, because they do absolutely nothing that you can do by yourself and take money for it. all communications with hackers could be conducted by your it department indipendently without any extra payments.

6. Do not try to decrypt your data via 3rd party software.
Most of ransomware use strong encryption algorthm and you can harm your files by using 3rd party decryption software.

Appearance of a site used to leak data stolen from Babuk Locker's victims (GIF):

Screenshot of files encrypted by Doydo ransomware (".doydo" extension):

Update November 3rd, 2021 - The source code of Babuk ransomware has been recently leaked in a forum, which gave cyber security experts an opportunity to release a decryptor for this ransomware. The tool developed by Avast is capable of restoring data encrypted Babuk ransomware with ".babuk", ".babyk", ".doydo", ".tortilla" and other extensions. You can download this tool and find more information in Avast's official website.

Screenshot of Avast's decryptor for Babuk ransomware:

Babuk Locker ransomware removal:

Instant automatic malware removal:

Manual threat removal might be a lengthy and complicated process that requires advanced IT skills. Combo Cleaner is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:

By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. To use full-featured product, you have to purchase a license for Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by RCS LT, the parent company of PCRisk.com.

Removal and file recovery procedure

If your files are encrypted with a new extension and a ransom note has appeared, you've been hit by ransomware. Don't pay. The procedure below works in order: contain the infection, identify the variant, remove the ransomware itself (so anything you restore doesn't get re-encrypted), and try to recover files using free decryption tools, Windows Volume Shadow Copies, or backups. Run a full system scan with Combo Cleaner to remove the infection - then move on to file recovery.

Common ransomware behaviors

VisibleEncrypts your files and renames them

The ransomware reads each file, encrypts the contents with the attacker's public key, and writes the encrypted bytes back to disk. Most variants also rename the file by appending a new extension - .net, .locked, .crypt, .lockbit, .djvu, etc. Without the matching private key, the encrypted files cannot be opened normally. Recovery depends on a free decryption tool, a recoverable Volume Shadow Copy, or a clean backup.

VisibleDrops a ransom note in every encrypted folder

A text or HTML file (usually named HOW_TO_DECRYPT.txt, README.txt, _readme.txt, or similar) is placed in every folder that contains encrypted files. The note explains the situation, lists a payment amount in cryptocurrency, gives a deadline, and provides a contact email or .onion site. Save the note - don't delete it. Its exact wording, the email address, and the bitcoin wallet are how you identify the variant in the next phase.

VisibleReplaces the desktop wallpaper

Many ransomware variants change the Windows wallpaper to a black or red image with the ransom message and instructions. The wallpaper is just a visual scare tactic - it doesn't add any actual capability and reverts to normal once the ransomware is removed. Photograph it before removal in case the contact details are useful for variant identification or for reporting to authorities.

HiddenDeletes Volume Shadow Copies

One of the first things modern ransomware does after launching is run vssadmin delete shadows /all /quiet to wipe Windows' built-in Volume Shadow Copies - the snapshots that Previous Versions and System Restore rely on. Some ransomware doesn't fully succeed (especially on systems where the user lacks full admin rights), leaving partial shadow copies recoverable. Phase 4 step 11 covers how to check what survived.

HiddenDisables Windows Defender and other security tools

Before encrypting, the ransomware tries to silence anything that could alert you or block it - Windows Defender real-time protection, third-party antivirus services, backup agents (Veeam, Acronis), and sometimes the Windows Event Log service. It often modifies Group Policy or registry keys to keep these off after reboot. Phase 3 step 9 explicitly turns Tamper Protection back on so the next ransomware attempt can't repeat the trick.

HiddenSpreads laterally to other PCs on the network

Network-aware ransomware (LockBit, Conti, BlackCat, Akira families) doesn't stop at the first machine. It scans for SMB shares, mapped drives, and other PCs on the same network, then encrypts whatever it can reach. On Windows domains, a single compromised user with admin rights can lead to all-domain encryption. This is why Phase 1 step 2 disconnects the network as the very first action - it stops the spread immediately.

HiddenSteals data before encrypting (double extortion)

Modern ransomware (LockBit, BlackCat / ALPHV, Akira, Cl0p, Royal) almost always exfiltrates data before encrypting. The attacker then runs a "double extortion" play: pay the ransom for decryption, plus pay again to prevent the stolen data from being leaked on the group's leak site. Paying the first ransom does not get the leaked data back - assume that anything the ransomware could read was uploaded. This is one more reason not to pay: the data is already out.

Tools you'll need

Combo Cleaner Antivirus 7-days free trial

Recommended primary scanner. VB100 certified. Removes the ransomware infection so file recovery doesn't get re-encrypted.

Microsoft Defender Offline Free · built-in

Built into Windows. Scans before Windows fully loads to catch persistence the running scanners miss.

Microsoft Safety Scanner (MSERT) Free

Microsoft's free on-demand scanner. Always-current signatures - the binary expires every 10 days.

ID Ransomware Free · web

Upload a ransom note and a sample encrypted file - identifies the variant family and tells you whether a free decryptor exists.

No More Ransom Project Free · web

Joint project of Europol, Dutch Police, and security vendors. Free decryption tools indexed by ransomware family.

Shadow Explorer Free

Browse Windows Volume Shadow Copies as a normal file tree - useful when ransomware partially failed to delete them.

Recuva Free

Deleted-file recovery. Long-shot for ransomware - only helps if the variant deleted unencrypted originals before encrypting copies.

Phase 1~ 5 min

Don't pay & contain

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1

Don't pay the ransom

1 min · read⚠ Do not skip

Paying the ransom does not guarantee you'll get your files back. Major ransomware response studies consistently show that a meaningful percentage of paying victims either receive a non-working decryptor, only partial decryption, or no decryptor at all. Beyond that:

• Paying confirms you as a willing target - re-attack rates within 12 months are high
• Several ransomware groups have been sanctioned (US OFAC, UK OFSI). Paying these groups may be illegal under sanctions law in your country
• The ransom funds the next attack - on you or someone else
• Modern ransomware almost always exfiltrates data first, so paying doesn't get the leaked data back. Assume anything the malware could read was uploaded
• Decryptors, even when they work, often leave files corrupted because the encryption itself was buggy or rushed

The path below tries every legal, free recovery option first. Pay only as an absolute last resort, after consulting a lawyer and your country's cyber crime authority.

2

Disconnect from the network and log out of cloud storage

2 minNo tool needed

Pull the Ethernet cable and turn off Wi-Fi on the affected PC. If multiple computers share the network, do the same on every machine you suspect could be affected, including any servers and NAS units.

Then sign out of cloud storage clients (OneDrive, Dropbox, Google Drive, iCloud) from their app settings. If you can, pause the sync. Some ransomware uses the running sync client to push encrypted versions over your clean cloud copies.

Why this matters

Modern ransomware spreads laterally across SMB shares, mapped drives, RDP, and reachable network neighbors. Disconnecting stops the spread the moment you do it. Logging out of cloud sync clients prevents the ransomware from encrypting the cloud copies of your files via the sync API.

3

Unplug external drives and USB storage

1 minNo tool needed

Safely eject any external drives, USB sticks, SD cards, and network-attached storage shares - then unplug them. If a drive was connected when the ransomware ran, the files on it may already be encrypted, but unplugging stops further damage.

Critically: don't reconnect any drive (including your most recent backup) to this PC until the ransomware is removed in Phase 3. Reconnecting an external backup to an actively-infected PC is the most common way that backup gets encrypted too.

Phase 2~ 5 min

Identify the variant

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4

Save the ransom note and a sample encrypted file

2 min

Copy the ransom note and one small encrypted file (under 1 MB) to a USB stick, or photograph the note with your phone. You'll need both for the variant identification step.

The ransom note is usually one of:

• A .txt file in every encrypted folder (typically HOW_TO_DECRYPT.txt, README.txt, or _readme.txt)
• An .html file with the same purpose
• A changed desktop wallpaper - photograph it
• A lock-screen interrupt that runs at startup - rarer

Important

Don't delete the note. Variant identification depends on its exact wording, the contact email, and the bitcoin wallet address. The note is also evidence if you report to authorities.

5

Identify the variant with ID Ransomware

Tool: ID Ransomware3 min

From a clean device (your phone is fine, or another PC that wasn't on the affected network), visit id-ransomware.malwarehunterteam.com. Upload the ransom note and the sample encrypted file. The site identifies the variant family and tells you whether a free decryptor exists.

Pro tip

ID Ransomware is run by the Malware Hunter Team. Files you upload are kept private - they're used for analysis, not published. If you're concerned about uploading data anyway, you can paste the contact email and bitcoin wallet from the note - those are often enough for identification.

Phase 3~ 30-45 min

Remove the ransomware

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The ransomware itself must be removed before any file recovery. If it's still active, anything you restore in Phase 4 gets re-encrypted within minutes.

6

Boot to Safe Mode with Networking and download the scanners

5 min

Safe Mode loads only the minimal Windows drivers, which prevents most ransomware from auto-running while you set up the scanners.

Windows 11: open Settings → System → Recovery, click Restart now next to Advanced startup. After the restart, click Troubleshoot → Advanced options → Startup Settings → Restart, then press 5 or F5.

Windows 10: click the Windows logo, hold Shift, click the Power icon and choose Restart. From the Choose-an-option screen, click Troubleshoot → Advanced options → Startup Settings → Restart, then press F5.

Once Safe Mode has loaded, turn Wi-Fi back on and download Combo Cleaner (used in step 8) and Microsoft Safety Scanner (used in step 9). Save both installers to your Desktop, then disconnect Wi-Fi again before scanning.

7

Run Microsoft Defender Offline

Tool: Built into Windows15 min

Reboot to normal Windows. Open Windows Security → Virus & threat protection → Scan options. Select Microsoft Defender Antivirus (offline scan) and click Scan now. The PC restarts into a stripped-down environment and scans the disk before Windows fully loads.

Why this comes first

Some ransomware variants drop bootkit components or kernel hooks that hide from any scanner running on the same Windows session that's already infected. A pre-boot offline scan sees the disk before the malware can load itself.

Recommended antivirus

Combo Cleaner

VB100 certified. Includes anti-trojan, registry/persistence scanning, and anti-spyware in one pass. The 7-day free trial is available.

Download Combo Cleaner

8

Run a full Combo Cleaner scan

Tool: Combo Cleaner20-40 min

Run the installer you downloaded in step 6 and start a full system scan (not the quick scan). Let it complete, review what it detected, and apply the recommended actions. Combo Cleaner quarantines the ransomware executable and the registry / scheduled-task entries that re-launch it on reboot.

9

Run Microsoft Safety Scanner and re-enable Defender

Tool: MSERT15 min

Run Microsoft Safety Scanner (MSERT.exe) as a second-opinion full scan. The binary expires every 10 days so the copy you downloaded has the latest signatures.

Once it finishes, open Windows Security → Virus & threat protection → Manage settings and confirm Real-time protection, Cloud-delivered protection, and Tamper Protection are all on. Many ransomware variants disable Defender during the attack - this is where you switch it back on so the next attempt can't repeat the trick.

Why a second scan

Different scanning engines catch different threats. Running an additional Microsoft scan after Combo Cleaner is the most underused verification step in malware removal - and free.

Phase 4~ 30-60 min · results vary

Try to recover files

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Try the steps in order. The first decryptor that works ends the recovery process - no need to do all four.

10

Check the No More Ransom Project for a free decryptor

Tool: nomoreransom.org★ Cleanest path if listed5 min

Visit nomoreransom.org and search the Decryption Tools list for the variant name returned by ID Ransomware. The project is run by Europol, the Dutch Police, and security vendors - everything listed is legitimate and free.

If a decryptor exists, download it onto a clean PC, copy it across, and follow its instructions exactly. Decryptors usually want you to point them at a sample encrypted file plus its known unencrypted version (sometimes any image you previously had a backup of works).

Free decryptors exist for parts of the STOP/Djvu, GandCrab, REvil, Avaddon, Conti and Hive families, among others. Most modern variants don't have public decryptors - if yours isn't listed, that's expected; move to the next step.

11

Try Windows Volume Shadow Copies

Tool: Shadow Explorer / vssadmin15 min

Windows automatically creates Volume Shadow Copies of files when System Restore points are made or scheduled backups run. Most ransomware tries to wipe these (vssadmin delete shadows /all /quiet), but the deletion sometimes fails partially - especially if the running user doesn't have full admin rights. When it does fail, snapshots survive that contain pre-encryption versions of your files.

First, check what's there. Open Command Prompt as Administrator and run:

vssadmin list shadows

If you see entries listed, shadow copies survived. To restore from them:

• Built-in: right-click any folder → Properties → Previous Versions tab. Pick a snapshot dated before the infection and restore.
• Better tool for browsing: install Shadow Explorer (free). It shows all snapshots as a normal file tree and lets you copy out only the files you want.

Why check this even when there's a decryptor

Shadow Copies recover the original files exactly, with no risk of decryption errors. If they survived, this is faster and cleaner than running a decryptor on the encrypted set.

12

Restore from cloud or external backup

Tool: your backup software30 min

If you have a backup that pre-dates the infection, this is the cleanest recovery available. Important precautions:

• Don't reconnect a backup drive until Phase 3 is complete. If the ransomware is still active, plugging in the backup encrypts it too.
• For cloud backups (OneDrive, Dropbox, Google Drive, iCloud), use the Version History feature to roll individual files back to pre-encryption versions.
• OneDrive specifically has a "Restore your OneDrive" feature: if it detected mass file changes, you can roll back the entire account up to 30 days. Sign in at OneDrive on the web, click the Settings gear, and choose Restore your OneDrive. Microsoft 365 subscribers also get ransomware detection alerts; non-subscribers get one free recovery.
• Verify the restored files open correctly before you delete the encrypted set. Test a few documents, photos, and any database / project files.

13

Try Recuva as a last-resort recovery

Tool: Recuva30 min

Recuva is a long shot, not a primary recovery tool. Most modern ransomware encrypts files in place - it reads the original, encrypts the data, and writes the encrypted bytes back to the same disk location. In that case, the original isn't deleted, just rewritten - and Recuva has nothing to find.

But for older or simpler variants that deleted originals before creating encrypted copies (rather than encrypting in place), Recuva can sometimes pull the originals from unallocated disk space. Worth trying as a last resort, especially before you use the disk much further.

If you try it:

• Stop using the disk as much as possible - every disk write reduces recovery odds
• Run Recuva from a USB stick, not from the affected disk
• Use Deep Scan mode (slower but the only mode worth running for this scenario)

Don't skip the steps above expecting Recuva to bail you out. It works in maybe 5-20% of cases, depending on the variant and how soon you try.

Phase 5~ 20 min + ongoing

Report & prevent re-infection

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14

Report the attack to authorities

10-20 min

Even if your files aren't recovered, your report helps authorities track variants, attribute groups, and warn future victims. In some jurisdictions (especially the US and UK) early reporting can sometimes help recall a wired ransom payment via banking partners.

United States: ic3.gov (FBI) + stopransomware.gov (CISA)

United Kingdom: reportfraud.police.uk (Report Fraud, the successor to Action Fraud) + NCSC

Canada: antifraudcentre.ca

Australia: ReportCyber

Spain: Policía Nacional (Oficina Virtual de Denuncias)

France: cybermalveillance.gouv.fr

Germany: BKA

Italy: Polizia Postale

Netherlands: Politie

Poland: CERT Polska

Portugal: CNCS

EU (other): your national CERT

Save the report number - banks, insurers, and credit bureaus will ask for it. If you operate a business, you may also have legal disclosure obligations (GDPR in the EU, state breach laws in the US) that run on a 72-hour clock.

15

Plan 3-2-1 backups going forward

30 min initial

The single best defense against ransomware is a tested backup. Use the 3-2-1 rule:

• 3 copies of your data
• 2 different storage media (e.g., internal drive + external drive)
• 1 offline / air-gapped copy (an external drive that isn't always connected)

Recommended cadence:

• Daily: cloud sync (OneDrive, Dropbox, Google Drive) - convenient, but vulnerable if the ransomware reaches the sync folder. The Version History feature is what saves you
• Weekly: external drive that you connect briefly, then disconnect - the air-gap is what protects against ransomware
• Monthly: a second external drive stored off-site (different physical location) - protects against fire, theft, flood

Important

Test the backup at least once. Open a few files from it, check sizes match, restore one to a different folder. An untested backup isn't a backup - it's a hope.

16

Patch the entry point and monitor for 30 days

5 min/day · 30 days

Most reinfections happen via the same vector that worked the first time. Until you've patched the entry point, watch for:

• Unusual disk activity, unexpected file modifications, or unfamiliar processes in Task Manager
• Unexpected reboots or new accounts you didn't create
• Defender or your antivirus turning itself off again

Common entry vectors and what to do about each:

• Phishing email with a malicious attachment - review email filters and train yourself / staff to recognise the patterns - see pcrisk's Phishing/Scam reference
• Exposed RDP with weak passwords - disable Remote Desktop from Settings → System → Remote Desktop if you don't need it. If you do, put it behind a VPN and require a long password plus MFA
• Unpatched VPN appliances or public-facing apps - check the vendor's advisories page and apply the latest firmware
• Cracked / pirated software - was the most common vector for STOP/Djvu in particular. Don't run software from torrent sites

Run a Combo Cleaner scan weekly for the first month. Update Windows, browsers, and applications aggressively.

Important: Removing a ransomware infection requires a full system scan, not a manual file delete. If you're not confident with the manual procedure, run an automated scan with Combo Cleaner and Windows Defender and stop there - that combination removes the vast majority of consumer ransomware variants. Then move to Phase 4 for file recovery, or to Phase 5 if your files are unrecoverable and you need to start fresh from a clean Windows install.

Frequently Asked Questions (FAQ)

How was my computer hacked and how did hackers encrypt my files?

Most threat actors send emails containing malicious files or links and use websites hosting cracked software (or cracking tools, key generators), P2P networks, third-party downloaders, free file hosting sites, and similar channels to trick users into infecting ransomware.

How to open ".__NIST_K571__", ".babuk", ".babuk2", or ".babyk" files?

Thes files cannot be opened until they are decrypted with the right decryption tool.

Where should I look for free decryption tools for Babuk Locker ransomware?

Files encrypted by Babuk Locker ransomware with ".babuk", ".babyk" and ".doydo" extensions can be decrypted with a tool that can be downloaded from here. In other cases, we recommend checking the No More Ransom project website (more information above).

I can pay you a lot of money, can you decrypt files for me?

We do not provide a decryption service. We also strongly recommend not to trust third parties offering paid decryption - they may be scammers or act as a man-in-the-middle. Typically, it is impossible to decrypt files without tools purchased from cybercriminals (unless ransomware is flawed). As mentioned above, certain files encrypted by Babuk Ransomware can be decrypted for free.

Will Combo Cleaner help me remove Babuk Locker ransomware?

Yes, Combo Cleaner will remove ransomware from the operating system. Using antivirus programs for ransomware removal prevents more data loss. However, files remain encrypted even after the removal.