Cerber ransomware virus - removal and decryption options

What kind of malware is Cerber?

Cerber (also called CRBR Encryptor) is a ransomware-type malware that infiltrates systems, encrypting various file types including .jpg, .doc, .raw, .avi, etc. Cerber adds a .cerber (some variants add .cerber2 or .cerber3) extension to each encrypted file.

Notice that some variants of this ransomware add random file extensions - for example: “.ba99”, ”.98a0", ".a37b", ".a563" etc. There are also variants of this ransomware that add .beef extension to encrypted files. Following successful infiltration, Cerber demands a ransom payment to decrypt these files.

It is stated that payment of the ransom must fall within the given time frame (seven days), otherwise the ransom amount will double.

Some variants of this ransomware disclose their versions - for example: "Cerber Ransomware 4.1.3", "Cerber Ransomware 4.1.5", "Cerber Ransomware 4.1.6", "Cerber Ransomware 5.0.0"  ( the latest variant demands a ransom of $499) etc.

Screenshot of a folder that was compromised by Cerber ransomware (all files are renamed and have a .cerber extension):

Overview of ransom notes

During encryption, Cerber creates three different files (#DECRYPT MY FILES#.txt, #DECRYPT MY FILES#.html, and #DECRYPT MY FILES#.vbs) containing step-by-step payment instructions (never variants use "_READ_THI$_FILE_.hta", "_HELP_HELP_HELP_random.hta", "_READ_THIS_FILE.hta", “_HELP_HELP_HELP_random.jpg", _R_E_A_D___T_H_I_S___random_.txt, _R_E_A_D___T_H_I_S___random_.hta and “_!!!_README_!!!_random_.hta”, “_!!!_README_!!!_random_.txt” files) in each folder containing the encrypted files.

The message within these files states that users can only decrypt their files using a decryptor developed by cyber criminals (called 'Cerber Decryptor'). The #DECRYPT MY FILES#.vbs file contains a VBScript, which when executed, plays the message, “Your documents, databases and other important files have been encrypted!” through the computer speakers.

To download the decryptor, a ransom payment of 1.24 BitCoin (at time of research, equivalent to $546.72) is required. If the ransom is not paid within seven days, it doubles to 2.48 BTC. It is also stated that users can only pay using the Tor browser and by following instructions within the indicated website.

Unfortunately, at time of research, there were no tools capable of decrypting files affected by Cerber. Therefore, the only solution to this problem is to restore your system from a backup.

After encrypting files, Cerber ransomware changes desktop wallpaper:

Update 1 December, 2016 - Cerber ransomware was updated by cyber criminals. The most noticeable changes include the use of red colour for the desktop wallpaper.

The ransom demanding message is now presented in _README_[RANDOM]_.hta file. Cyber criminals no longer provide the version number of this ransomware. The ransom amount at the time of writing this article was $499 payable in Bitcoins.

Update June 15, 2017 - Cyber criminals have updated their ransom demanding message presented in a .txt file (_R_E_A_D___T_H_I_S___random_.txt). Here’s a screenshot of this updated file:

Text presented in _R_E_A_D___T_H_I_S___random_.txt file:

Hi, I'am CERBER RANSOMWARE ;)
 -----
 Y0UR D0CUMENTS, PHOTOS, DATABASES AND OTHER IMPORTANT FILES HAVE BEEN ENCRYPTED!
 -----
 The only way to decrypt your files is to receive the private key and decryption program.
 To receive the private key and decryption program go to any decrypted folder,
 inside there is the special file (*_R_E_A_D___T_H_I_S_*) with complete instructions
 how to decrypt your files.
 If you cannot find any (*_R_E_A_D___T_H_I_S_*) file at your PC, follow the instructions below:
 -----
 1. Download "Tor Browser" from https://www.torproject.org/ and install it.
 2. In the "Tor Browser" open your personal page here:
 http://p27dokhpz2n7nvgr.onion/
 Note! This page is available via "Tor Browser" only.
 -----
 Also you can use temporary addresses on your personal page without using "Tor Browser".
 -----
 1. http://p27dokhpz2n7nvgr.12nwsv.top/
 -----
 Note! These are temporary addresses! They will be available for a limited amount of time!
 -----

Victims of Cerber ransomware can use a decrypter called “Trend Micro Ransomware File Decryptor tool” to decrypt their files for free. Download is HERE. (Unfortunately this tool is no longer available) You can view a video tutorial of how to use this tool HERE. Here’s a screenshot of this tool:

Update 17 August 2016 - Check Point Software Technologies Ltd. company has released a decrypter for Cerber ransomware. At the time of testing it was able to decrypt files with .cerber and .cerber2 extensions. To decrypt their files victims should visit THIS website and follow the simple 7 steps to decrypt their files for free.

Unfortunately cyber criminals have updated their ransomware and this tool no longer works. Here’s a screenshot of Cerber Ransomware Dceryption Tool website:

Text presented on the wallpaper of Cerber ransomware:

You documents, photos, databases and other important files have been encrypted!
If you understand all importance of the situation then we propose to you to go directly to your personal page where you will receive the complete instructions and guarantees to restore your files. There is a list of temporary addresses to go on your personal page.

A screenshot of Cerber ransomware website (used to provide victims with ransom payment instructions, provide support, etc.):

Text presented in the homepage of Cerber ransomware:

Your documents, photos, databases and other important files have been encrypted! To decrypt your files you need to buy the special software – «Cerber Decryptor». All transactions should be performed via Bitcoin network only. Within 5 days you can purchase this product at a special price:  0.750 (≈ $518). After 5 days the price of this product will increase up to:  1.500 (≈ $1036).

As with other crypto ransomware, Cerber shares many similarities with many other malware infections such as Locky, CryptoWall, CTB-Locker, Crypt0L0cker, and TeslaCrypt. All have identical behavior - they encrypt files and encourage users to pay a ransom to decrypt them.

The only difference between these viruses is the algorithm used to encrypt the files and size of ransom. Be aware that there is no guarantee that your files will ever be decrypted even after paying the ransom. Paying is equivalent to sending your money for cyber criminals - you merely support their malicious businesses.

Therefore, never pay the ransom and do not attempt to contact these people. Malware such as Cerber is mostly proliferated via malicious e-mail attachments, peer-to-peer (P2P) networks (for example, Torrent), fake software updates, and trojans.

Be cautious when opening attachments from unrecognized emails and ensure that your chosen files are downloaded from trusted sources. Furthermore, keep all installed software up-to-date and use a legitimate anti-virus or anti-spyware suite.

Screenshot of README.hta file (updated variant of Cerber ransomware now uses this file to open it's ransom demanding website):

Cerber website FAQ:

Question: How can i decrypt my files after payment?
Answer: After payment, you can download the «Cerber Decryptor» from your personal page. We guarantee that all your files will be decrypted!
Question: My files was infected more then month ago, can i still decrypt it with your software?
Answer: Yes, you can still decrypt your files after the payment!

Cerber website Support:

In case of any problems with payment or having any other questions, please contact us via the contact form.

Cerber website “Decrypt 1 files for Free”:

We give you the opportunity to decipher 1 file free of charge! You can make sure that the service really works and after payment for the «Cerber Decryptor» program you can actually decrypt the files!

Cerber ransomware distributed via spam e-mail attachments (using infected .WSF and .DOC files):

Cerber ransomware is delivered by a rogue document attached to spam emails. Once users open the document, they are encouraged to enable malicious macros - the ransomware then starts to encrypt victims' data:

A variant of Cerber ransomware that appends ".beef" extension to encrypted files:

After infiltrating the victim's computer, Cerber ransomware targets files with these extensions:

.gif, .groups, .hdd, .hpp, .log, .m2ts, .m4p, .mkv, .mpeg, .ndf, .nvram, .ogg, .ost, .pab, .pdb, .pif, .png, .qed, .qcow, .qcow2, .rvt, .st7, .stm, .vbox, .vdi, .vhd, .vhdx, .vmdk, .vmsd, .vmx, .vmxf, .3fr, .3pr, .ab4, .accde, .accdr, .accdt, .ach, .acr, .adb, .ads, .agdl, .ait, .apj, .asm, .awg, .back, .backup, .backupdb, .bay, .bdb, .bgt, .bik, .bpw, .cdr3, .cdr4, .cdr5, .cdr6, .cdrw, .ce1, .ce2, .cib, .craw, .crw, .csh, .csl, .db_journal, .dc2, .dcs, .ddoc, .ddrw, .der, .des, .dgc, .djvu, .dng, .drf, .dxg, .eml, .erbsql, .erf, .exf, .ffd, .fh, .fhd, .gray, .grey, .gry, .hbk, .ibd, .ibz, .iiq, .incpas, .jpe, .kc2, .kdbx, .kdc, .kpdx, .lua, .mdc, .mef, .mfw, .mmw, .mny, .mrw, .myd, .ndd, .nef, .nk2, .nop, .nrw, .ns2, .ns3, .ns4, .nwb, .nx2, .nxl, .nyf, .odb, .odf, .odg, .odm, .orf, .otg, .oth, .otp, .ots, .ott, .p12, .p7b, .p7c, .pdd, .pem, .plus_muhd, .plc, .pot, .pptx, .psafe3, .py, .qba, .qbr, .qbw, .qbx, .qby, .raf, .rat, .raw, .rdb, .rwl, .rwz, .s3db, .sd0, .sda, .sdf, .sqlite, .sqlite3, .sqlitedb, .sr2, .srf, .srw, .st5, .st8, .std, .sti, .stw, .stx, .sxd, .sxg, .sxi, .sxm, .tex, .wallet, .wb2, .wpd, .x11, .x3f, .xis, .ycbcra, .yuv, .contact, .dbx, .doc, .docx, .jnt, .jpg, .msg, .oab, .ods, .pdf, .pps, .ppsm, .ppt, .pptm, .prf, .pst, .rar, .rtf, .txt, .wab, .xls, .xlsx, .xml, .zip, .1cd, .3ds, .3g2, .3gp, .7z, .7zip, .accdb, .aoi, .asf, .asp, .aspx, .asx, .avi, .bak, .cer, .cfg, .class, .config, .css, .csv, .db, .dds, .dwg, .dxf, .flf, .flv, .html, .idx, .js, .key, .kwm, .laccdb, .ldf, .lit, .m3u, .mbx, .md, .mdf, .mid, .mlb, .mov, .mp3, .mp4, .mpg, .obj, .odt, .pages, .php, .psd, .pwm, .rm, .safe, .sav, .save, .sql, .srt, .swf, .thm, .vob, .wav, .wma, .wmv, .xlsb,3dm, .aac, .ai, .arw, .c, .cdr, .cls, .cpi, .cpp, .cs, .db3, .docm, .dot, .dotm, .dotx, .drw, .dxb, .eps, .fla, .flac, .fxg, .java, .m, .m4v, .max, .mdb, .pcd, .pct, .pl, .potm, .potx, .ppam, .ppsm, .ppsx, .pptm, .ps, .r3d, .rw2, .sldm, .sldx, .svg, .tga, .wps, .xla, .xlam, .xlm, .xlr, .xlsm, .xlt, .xltm, .xltx, .xlw, .act, .adp, .al, .bkp, .blend, .cdf, .cdx, .cgm, .cr2, .crt, .dac, .dbf, .dcr, .ddd, .design, .dtd, .fdb, .fff, .fpx, .h, .iif, .indd, .jpeg, .mos, .nd, .nsd, .nsf, .nsg, .nsh, .odc, .odp, .oil, .pas, .pat, .pef, .pfx, .ptx, .qbb, .qbm, .sas7bdat, .say, .st4, .st6, .stc, .sxc, .sxw, .tlg, .wad, .xlk, .aiff, .bin, .bmp, .cmt, .dat, .dit, .edb, .flvv

Screenshot of #DECRYPT MY FILES#.html file:

Screenshot of #DECRYPT MY FILES#.txt file:

Cerber Decryptor download instructions:

How to get ?
1. Create a Bitcoin Wallet (we recommend Blockchain.info)
2. Buy necessary amount of Bitcoins
Do not forget about the transaction commission in the Bitcoin network (0.0005 BTC).
3. Send 1.24 Bitcoins to the following Bitcoin address: -
4. Control the amount transaction at he panel below.
5. Get a link and download the software.

Text presented in #DECRYPT MY FILES#.txt file:

CERBER

Cannot your find the files you need? Is the content of the files that you looked for not readable? It is normal because the files’ names, as well as the data in your files have been encrypted. Great!!! You have turned to be a part of a big community #CerberRansomware.

#########################################################################

!!! If you are reading this message it means the software
!!! “Cerber Ransomware” has been removed from your computer.

#########################################################################

What is encryption? Encryption is a reversible modification of information for security reasons but providing full access to it for authorised users. To become an authorised user and keep the modification absolutely reversible (in other words to have a possibility to decrypt your files) you should have an individual private key. But not only it. It is required also to have the special decryption software (in your case “Cerber Decryptor” software) for safe and complete decryption of all your files and data.

#########################################################################

Everything is clear for me but what should I do? The first step is reading these instructions to the end. Your files have been encrypted with the “Cerber Ransomware” software; the instructions (“#DECRYPT MY FILES #.html” and “# DECRYPT MY FILES #.txt”) in the folders with your encrypted files are not viruses, they will help you. After reading this text the most part of people start searching in the Internet the words the “Cerber Ransomware” where they find a lot of ideas, recommendation and instructions. It is necessary to realise that we are the ones who closed the lock on your files and we are the only ones who have this secret key to open them.

!!! Any attempts to get back you files with the third-party tools can
!!! be fatal for your encrypted files.

The most part of the tried-party software change data with the encrypted files to restore it but this cases damage to the files. Finally it will be impossible to decrypt your files. When you make a puzzle but some items are lost, broken or not put in its place - the puzzle items will never match, the same way the third-party software will ruin your files completely and irreversibly. You should realise that any intervention of the third-party software to restore files encrypted with the “Cerber Ransomware” software may be fatal for your files.

#########################################################################

!!! There are several plain steps to restore your files but if you do
!!! not follow them we will not be able to help you, and we will not try
!!!since you have read this warning already.

#########################################################################

For you information the software to decrypt your files (as well as the private key provided together) are paid products. After purchase of the software package you will be able to:

1. decrypt all you files;
2. work with your documents;
3. view you photos and other media;

#########################################################################

What should you do with these addresses? If you read the instructions in TXT format (if you have instructions in HTML (the file with an icon of you Internet browser) then the easiest way is to run it): 1. take a look at the first address 2. select it with the mouse cursor holding the left mouse button and moving the cursor to the right; 3. release the left mouse button and press the right one; 4. select “Copy” in the appeared menu; 5. run you Internet browser (if you do not know what it is run the Internet Explorer); 6. move the mouse cursor to the address bar of the browser (this is the place where the site address is written); 7. click the right mouse button in the field where the site address is written; 8. select the button “Insert” in the appeared menu; 9. then you will see the address appeared there; 10. press ENTER; 11. the site should be loaded; if it is not loaded repeat the same instructions with the second address and continue until the last address if falling. If for some reason the site cannot be opened check the connection to the Internet; if the site still cannot be opened take a look at the instructions on omitting the post about working with the addresses in the HTML instructions.

#########################################################################

Additional information: You will find the instructions for restoring your files in those folders where you have encrypted files only. The instructions are made in two file formats - HTML and TXT for your convenience. Unfortunately antivirus companies cannot protect or restore your files but they can make the situation worse removing the instructions how to restore your encrypted files. The instructions are not viruses; they have informative nature only, so any claims on the absence of any instruction files you can send to your antivirus company.

#########################################################################

Cerber Ransomware Project is not malicious and is not intended to harm a person and his/her information data. The project is created for the sole purpose of instruction regarding information security, as well as certification of antivirus software for their suitability for data protection. Together we make the Internet a better and safer place.

#########################################################################

If you look through this text in the Internet and realise that something is wrong with your files but you do not have any instructions to restore your files, please contact your antivirus support.

#########################################################################

Remember that the worst situation already happened and not it depends on your determination and speed of you actions the further life of your files.

Another variant of Cerber ransomware (goes by the name of CRBR):

Screenshot of the pop-up window:

Text within the pop-up (available in multiple languages):

CRBR ENCRYPTOR
Instructions

Select your language:

 

English
العربية
中文
Nederlands
Français
Deutsch
Italiano
日本語
한국어
Polski
Português
Español
Türkçe

Can't you find the necessary files?
Is the content of your files not readable?

It is normal because the files' names and the data in your files have been encrypted by "CRBR Encryptor".

It meoans your files are NOT damaged! Your files are modified only. This modification is reversible.
FiF4MUrom now it is not possible to use your files until they will be decrypted.

The only way to dectrypt your files safely is to buy the special decryption software "CRBR Decryptor".

Any attempts to restore your files with the third-party software will be fatal for your files!

--------------------------------------------------------------------------------

You can protected with purchasing of the decryption software at your personal page:

Please wait...hxxp://xpcx6erilkjced3j.14pxvn.top/F16B-26B2-FF51-0006-4A31

--------------------------------------------------------------------------------
hxxp://xpcx6erilkjced3j.onion.link/F16B-26B2-FF51-0006-4A31
--------------------------------------------------------------------------------
hxxp://xpcx6erilkjced3j.onion.nu/F16B-26B2-FF51-0006-4A31
--------------------------------------------------------------------------------
hxxp://xpcx6erilkjced3j.onion.cab/F16B-26B2-FF51-0006-4A31
--------------------------------------------------------------------------------
hxxp://xpcx6erilkjced3j.onion.to/F16B-26B2-FF51-0006-4A31
If this page cannot be opened  click here  to get a new address of your personal page.

If the addre1YLUwEss of your personal page is the same as before after you tried to get a new one,
you can try to get a new address in one hour.

At thZhHis page you will receive the complete instructions how to buy the decryption software for restoring all your files.

Also at this page you will be able to restore any one file for free to be sure "CRBR Decryptor" will help you.

--------------------------------------------------------------------------------

If your personal page is not availakble for a long period there is another way to open your personal page - instamoW9ZJMEEllation and use of Tor Browser:

1. run your Internet browser (if you do not know what it is run the Internet Explorer);
2. enter or copy the address hxxps://www.torproject.org/download/download-easy.html.en into the address bar of your browser and press ENTER;
3. wait for the site loading;
4. on the site you will be offered to download Tor Browser; download and run it, follow the installation instructions, wait until the installation is completed;
5. run Tor Browser;
6. connect with the buttNon "Connect" (if you use the English version);
7. a normal Internet browser window will be opened after the initialization;
8. type or copy the address
hxxp://xpcx6erilkjced3j.onion/F16B-26B2-FF51-0006-4A31
in this browser address bar;
9. press ENTER;
10.
the site shohuuld be loaded; if for some reason the site is not loyLading wait for a moment and try again.
If you have any problems during installation or use of Tor Browser, please, visit hxxps://www.youtube.com and type request in the search bar "Install Tor Browser Windows" and you will find a lot of training videos about Tor Browser installation and use.

Screenshot of the created text file ("_R_E_A_D___T_H_I_S_[random_string].txt"):

Text within this file:

Hi, I'am CRBR ENCRYPTOR ;)
 
 -----
 
 ALL YOUR DOCUMENTS, PHOTOS, DATABASES AND OTHER IMP0RTANT FILES HAVE BEEN ENCRYPTED!
 
 -----
 
 The only one way to decrypt your files is to receive the private key and decryption program.
 
 To receive the private key and decryption program go to any decrypted folder,
 inside there is the special file (*_R_E_A_D___T_H_I_S_*) with complete instructions
 how to decrypt your files.
 
 If you cannot find any (*_R_E_A_D___T_H_I_S_*) file at your PC, follow the instructions below:
 
 -----
 
 1. Download "Tor Browser" from hxxps://www.torproject.org/ and install it.
 
 2. In the "Tor Browser" open your personal page here:
 
 hxxp://xpcx6erilkjced3j.onion/F16B-26B2-FF51-0006-4A31
 
 Note! This page is available via "Tor Browser" only.
 
 -----
 
 Also you can use temporary addresses on your personal page without using "Tor Browser".
 
 -----
 
 1. hxxp://xpcx6erilkjced3j.tor2web.org/F16B-26B2-FF51-0006-4A31
 
 2. hxxp://xpcx6erilkjced3j.onion.link/F16B-26B2-FF51-0006-4A31
 
 3. hxxp://xpcx6erilkjced3j.onion.nu/F16B-26B2-FF51-0006-4A31
 
 4. hxxp://xpcx6erilkjced3j.onion.cab/F16B-26B2-FF51-0006-4A31
 
 5. hxxp://xpcx6erilkjced3j.onion.to/F16B-26B2-FF51-0006-4A31
 
 -----
 
 Note! These are temporary addresses! They will be available for a limited amount of time!
 
 -----

Screenshot of desktop wallpaper:

Text within this image:

CRBR ENCRYPTOR
 
 YOUR DOCUMENTS, PHOTOS, DATABASES AND OTHER IMPORTANT FILES HAVE BEEN ENCRYPTED!
 
 The only way to decrypt your files is to receive the private key and decryption program.
 
 To receive the private key and decryption program go to any decrypted folder - inside there is special file (*_R_E_A_D___T_H_I_S_*) with complete instructions how to decrypt your files.
 
 If you cannot find any (*_R_E_A_D___T_H_I_S_*) file at your PC, follow the instructions below:
 
 1. Download "Tor Browser" from hxxps://www.torproject.org/ and install it.
 2. In the "Tor Browser" open your personal page here:
 
hxxp://xpcx6erilkjced3j.onion/F16B-26B2-FF51-0006-4A31

Note! This page is available via "Tor Browser" only.

Screenshot of files encrypted by this variant ("[random_name].[random_extension]" filename pattern):

Cerber 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?

Users infect computers with ransomware via files or links received from threat actors via email, downloads from unreliable sources (e.g., P2P networks, third-party downloaders, torrent sites), web pages hosting cracked/pirated software, fake installers, and other ways. Cybercriminals use different tactics to trick users into executing ransomware.

How to open files encrypted by Cerber ransomware?

These files cannot be opened without decryption tools.

Where should I look for free decryption tools for Cerber ransomware?

In case of a ransomware attack you should check 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. As a rule, victims are forced to pay threat actors for decryption tools. Third parties offering to decrypt files for money should not be paid. Most of them are scammers or act as man-in-the-middle.

Will Combo Cleaner help me remove Cerber ransomware?

Combo Cleaner will scan the operating system for threats and eliminate active ransomware. Antivirus software does not decrypt encrypted files. However, it removes ransomware to prevent additional encryptions.