How to remove Kodc ransomware from the operating system?

Also Known As: Kodc virus
Distribution: Moderate
Damage level: Severe

Kodc ransomware removal instructions

What is Kodc?

Kodc is a malicious program, belonging to the Stop/Djvu ransomware family. Its discovery is credited to Michael Gillespie. Systems infected with this malware have their data encrypted and their respective users receive ransom demands for the decryption. As Kodc ransomware encrypts, all files are appended with the ".kodc" extension. For example, a filename like "1.jpg" would appear as "1.jpg.kodc" - following encryption, and so on for all of the affected files. After this process is finished, a text file - "_readme.txt" is created on the desktop.

The text file contains the ransom note, which informs victims of the encryption. According to the message, strongest encryption and unique key were used to "lock" the data. However, users are reassured that recovery is possible. The only way to decrypt the files is to purchase decryption tools/keys from the cyber criminals behind the attack. The price of said tools is stated to be $980, yet it can be halved ($490), if contact with the malware's developers is established within the first 72 hours. This can be done by writing to the email addresses provided in the note. To verify the possibility of decryption, the criminals offer free decryption of one file, given if it does not contain valuable information. This test file can be attached to the email victims are to send. Should users fail to receive a response within 6 hours, they are instructed to inspect their "Spam/Junk" email folders for it. In most cases of ransomware encryption, decryption is impossible without the interference of the cyber criminals responsible for the infection. It might be viable, if the ransomware in question is still in development and/or has significant flaws/bugs. Whatever the case, it is strongly advised against meeting the ransom demands. Since often, despite paying - users do not receive the necessary tools/software to decrypt their data. Which leaves them with worthless files that are damaged beyond repair and they experience financial losses. Eliminating Kodc from the operating system will prevent it from further encryptions, however it will not restore already compromised data. The sole solution is recovering it from a backup, if one was made before the attack and was stored in a different location.

Screenshot of a message encouraging users to pay a ransom to decrypt their compromised data:

Kodc decrypt instructions (_readme.txt)

BWNGMarkCryLock and 5SS5C are examples of other ransomware-type programs. They are designed to encrypt data and demand payment for the appropriate decryption tools/software. Key differences between them include: the cryptographic algorithm they use (symmetric or asymmetric) and the ransom size. The latter range between three and four digit sums (in USD). Typically, digital currencies (e.g. cryptocurrencies, pre-paid vouchers, etc.) are used for these payments, as transactions of such are difficult/impossible to trace. To ensure data safety, it is advised to store backups in remote severs and/or unplugged storage devices. Ideally, backups should be stored in several separate locations.

How did ransomware infect my computer?

The most common ways that ransomware and other malware spread are through trojans, spam campaigns, untrustworthy download sources, software "cracking" (activation) tools and fake updaters. Trojans are malicious programs with a wide variety of heinous abilities, which can include download/installation of additional malware. "Spam campaign" is a term used to refer to deceptive emails send on a large scale. These letters are usually presented as "important", "official", "urgent" and so on. They have infectious files attached to them (and/or contain links leading to said files). The virulent attachments can be in various formats (e.g. archive and executable files, PDF and Microsoft Office documents, JavaScript, etc.) and when the are opened - the infection is initiated. Unofficial and free file-hosting websites, P2P sharing networks (BitTorrent, Gnutella, eMule, etc.) and other third party downloaders - are considered to be untrustworthy download channels. Any sources considered as such - can offer malicious content for downloading, disguised as ordinary software and/or bundled (i.e. packed together) with it. Rather than activate licensed product, illegal activation ("cracking") tools can download/install malware. Fraudulent updates infect systems by exploiting weaknesses of outdated programs and/or by simply installing malware instead of the promised updates.

Threat Summary:
Name Kodc virus
Threat Type Ransomware, Crypto Virus, Files locker
Encrypted Files Extension .kodc
Ransom Demanding Message _readme.txt
Ransom Amount $980/$490
Cyber Criminal Contact and
Detection Names AVG (Win32:TrojanX-gen [Trj]), BitDefender (Trojan.GenericKD.42261545), ESET-NOD32 (A Variant Of Win32/Kryptik.HAIP), Kaspersky (, Full List Of Detections (VirusTotal)
Rogue Process Name updatewin.exe
Symptoms Cannot open files stored on your computer, previously functional files now have a different extension (for example, my.docx.locked). A ransom demand message is displayed on your desktop. Cyber criminals demand payment of a ransom (usually in bitcoins) to unlock your files.
Additional Information This malware is designed to show a fake Windows Update window and modify the Windows "hosts" file to prevent users from accessing cyber security websites (more information below).
Distribution methods Infected email attachments (macros), torrent websites, malicious ads, unofficial activation and updating tools.
Damage All files are encrypted and cannot be opened without paying a ransom. Additional password-stealing trojans and malware infections can be installed together with a ransomware infection.

To eliminate Kodc virus our malware researchers recommend scanning your computer with Spyhunter.
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How to protect yourself from ransomware infections?

It is highly recommended not to open suspect and/or irrelevant emails, especially ones received from unknown/suspicious addresses. Any attachments (or links) found in dubious mail - must never be opened, as it can trigger the files to begin downloading/installing malware. All downloads should be done from official and verified sources. The same extends to program activation and updating, it should be done using functions/tools provided by genuine developers. Illegal activation ("cracking") tools and third party downloaders can cause an infection, therefore they are advised against use. It is paramount to device health and user safety - to have a reputable anti-virus/anti-spyware suite installed and kept up-to-date. Furthermore, this software is to be used for regular system scans and removal of detected/potential threats. If your computer is already infected with Kodc, we recommend running a scan with Spyhunter for Windows to automatically eliminate this ransomware.

Text presented in Kodc ransomware's text file ("_readme.txt"):


Don't worry, you can return all your files!
All your files like photos, databases, documents and other important are encrypted with strongest encryption and unique key.
The only method of recovering files is to purchase decrypt tool and unique key for you.
This software will decrypt all your encrypted files.
What guarantees you have?
You can send one of your encrypted file from your PC and we decrypt it for free.
But we can decrypt only 1 file for free. File must not contain valuable information.
You can get and look video overview decrypt tool:
Price of private key and decrypt software is $980.
Discount 50% available if you contact us first 72 hours, that's price for you is $490.
Please note that you'll never restore your data without payment.
Check your e-mail "Spam" or "Junk" folder if you don't get answer more than 6 hours.

To get this software you need write on our e-mail:

Reserve e-mail address to contact us: 

Screenshot of files encrypted by Kodc (".kodc" extension):

Files encrypted by Kodc ransomware (.kodc extension)

Screenshot of Kodc ransomware's process on Windows Task Manager ("updatewin.exe")

Kodc ransomware process on Task Manager (updatewin.exe)

Screenshot of fake Windows update pop-up displayed during the encryption:

Fake Windows pop-up displayed by Kodc during the encryption

IMPORTANT NOTE! - As well as encrypting data, ransomware-type infections from the Djvu malware family also add a number of entries to the Windows "hosts" file. The entries contain URLs of various websites, most of which are related to malware removal. This is done to prevent users from accessing malware security websites and seeking help. Our website ( is also on the list. Removing these entries, however, is simple - you can find detailed instructions in this article (note that, although the steps are shown in the Windows 10 environment, the process is virtually identical on all versions of the Microsoft Windows operating system).

Screenshot of websites added to Windows hosts file:

Tro Ransomware adding websites to Windows Hosts file

There are currently two versions of Djvu ransomware infections: old and new. The old versions were designed to encrypt data by using a hard-coded "offline key" whenever the infected machine had no internet connection or the server was timing out/not responding. Therefore, some victims were able to decrypt data using a tool developed by cyber security researcher, Michael Gillespie, however, since the encryption mechanism has been slightly changed (hence the new version, released in August, 2019), the decrypter no longer works and it is not supported anymore. If your data has been encrypted by an older version, you might be able to restore it with the another tool developed by Emsisoft and Michael Gillespie. It supports a total of 148 Djvu's variants and you can find more information, as well as download link and decryption instructions in Emsisoft's official page.

Screenshot of Djvu decryption tool by Emsisoft and Michael Gillespie:

Djvu ransomware decrypter by Michael Gillespie and Emsisoft

Additionally, Emsisoft is now providing a service that allows to decrypt data (again, only if it was encrypted by Djvu variants released before August, 2019) for those victims who have a pair of the same file before and after the encryption. All victims have to do is upload a pair of original and encrypted file to Emsisoft's Djvu decryption page and download the aforementioned decryption tool (the download link will be provided after uploading files). Note that the file processing may take some time so be patient. It is also worth mentioning that the system must have an Internet connection during the entire decryption process, otherwise it will fail.

Screenshot of Emsisoft's Djvu decryption service page:

Djvu ransomware decryption service by Emsisoft

Kodc ransomware removal:

Instant automatic removal of Kodc virus: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Spyhunter is a professional automatic malware removal tool that is recommended to get rid of Kodc virus. Download it by clicking the button below:
▼ DOWNLOAD Spyhunter By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

Quick menu:

Step 1

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in "Safe Mode with Networking":

Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in "Safe Mode with Networking":

Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button. In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.

windows 10 safe mode with networking

Video showing how to start Windows 10 in "Safe Mode with Networking":

Step 2

Log in to the account infected with the Kodc virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.

If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.

Video showing how to remove ransomware virus using "Safe Mode with Command Prompt" and "System Restore":

1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.

Boot your computer in Safe Mode with Command Prompt

2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.

system restore using command prompt type cd restore

3. Next, type this line: rstrui.exe and press ENTER.

system restore using command prompt rstrui.exe

4. In the opened window, click "Next".

restore system files and settings

5. Select one of the available Restore Points and click "Next" (this will restore your computer system to an earlier time and date, prior to the Kodc ransomware virus infiltrating your PC).

select a restore point

6. In the opened window, click "Yes".

run system restore

7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining Kodc ransomware files.

To restore individual files encrypted by this ransomware, try using Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of Kodc are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.

To restore a file, right-click over it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the "Restore" button.

Restoring files encrypted by CryptoDefense

If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode making its removal complicated. For this step, you require access to another computer.

To regain control of the files encrypted by Kodc, you can also try using a program called Shadow Explorer. More information on how to use this program is available here.

shadow explorer screenshot

To protect your computer from file encryption ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and EasySync CryptoMonitor, which artificially implant group policy objects into the registry to block rogue programs such as Kodc ransomware.

Note that Windows 10 Fall Creators Update includes a "Controlled Folder Access" feature that blocks ransomware attempts to encrypt your files. By default, this feature automatically protects files stored in the Documents, Pictures, Videos, Music, Favorites, and Desktop folders.

Controll Folder Access

Windows 10 users should install this update to protect their data from ransomware attacks. Here is more information on how to get this update and add an additional protection layer from ransomware infections.

HitmanPro.Alert CryptoGuard - detects encryption of files and neutralises any attempts without need for user-intervention:

hitmanproalert ransomware prevention application

Malwarebytes Anti-Ransomware Beta uses advanced proactive technology that monitors ransomware activity and terminates it immediately - before reaching users' files:

malwarebytes anti-ransomware

  • The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups. More information on online backup solutions and data recovery software Here.

Other tools known to remove Kodc ransomware:

About the author:

Tomas Meskauskas

Tomas Meskauskas - expert security researcher, professional malware analyst.

I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats. Contact Tomas Meskauskas.

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Malware activity

Global malware activity level today:

Medium threat activity

Increased attack rate of infections detected within the last 24 hours.

QR Code
Kodc virus QR code
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