How to remove 0day0 ransomware from the operating system?

Also Known As: 0day0 virus
Distribution: Low
Damage level: Severe

0day0 ransomware removal instructions

What is 0day0?

0day0 is the name of a malicious program, belonging to the Dharma ransomware family. This malware's discovery is credited to dnwls0719. 0day0 encrypts data in order to demand a ransom for the decryption tools/software. During the encryption process, files are renamed following this pattern: original filename, unique ID assigned to the victim, cyber criminals' email address and the ".0day0" extension. For example, a file like "1.jpg" would appear as something similar to "1.jpg.id-1E857D00.[day_0@aol.com].0day0", and so on for all of the affected files. Once this process is complete, ransom notes are created in a pop-up window and "FILES ENCRYPTED.txt" text file.

The text file ("FILES ENCRYPTED.txt") informs users that their data has been encrypted. If they wish to restore the files, victims are instructed to establish contact with the cyber criminals behind 0day0 ransomware, via email. The text presented in the pop-up window provides more information. It adds that the users' letters are to include the ID assigned to them. Additionally, the note warns that renaming the encrypted files and/or attempting to decrypt them with third party software - may result in permanent data loss. In many cases of ransomware attacks, without interference of the criminals responsible - decryption is impossible. It may be, if the malware is still in development and/or has bugs (flaws). Whatever the case, it is expressly advised against communicating with and/or meeting the demands of cyber criminals. As often, despite paying - victims do not receive the promised decryption tools/software. Therefore, they experience financial loss and their files remain encrypted - essentially, worthless. To prevent 0day0 from further encryptions, it must be eliminated from the operating system. Unfortunately, removal will not restore already compromised data. The only solution is recovering it from a backup. Given, if one was created before the infection and was stored in a separate location (so as not to have been affected by 0day0).

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

0day0 decrypt instructions (pop-up)

HimynameisransomTrixBest Recovery and Noblis are a couple examples of other ransomware-type programs. They are designed to encrypt data and demand payment for the decryption. There are two main differences in-between them: the cryptographic algorithm they use (symmetric or asymmetric) and the size of the demanded sum. The latter tend to vary from three to four digits in USD. Digital currencies (e.g. cryptocurrencies, pre-paid vouchers, etc.) are typically used for the ransoms, due to transactions of them being difficult/impossible to trace. To ensure data safety, it is recommended to keep backups in remote servers and/or unplugged storage devices (ideally, in multiple different locations).

How did ransomware infect my computer?

The most common malware (ransomware included) proliferation methods include: spam campaigns, trojans, illegal activation tools ("cracks"), fake updaters and dubious download channels. The term "spam campaign" is used to define a large scale operation, during which thousands of deceptive/scam emails are sent. This mail is usually disguised as "official", "important", "urgent", "priority" and similar. These letters have malicious files attached to them or contain download links of such. Infectious files can be in various formats, e.g. Microsoft Office and PDF documents, archives (ZIP, RAR), executables (.exe, .run), JavaScript, etc. When they are executed, run or otherwise opened - download/installation of malware is initiated. Trojans are malicious programs, some types of which can cause chain infections (i.e. download/install additional malware). Illegal activation ("cracking") tools can download/install malicious software instead of activating licensed product. Illegitimate updaters cause infections by exploiting flaws of outdated products and/or by installing malware, rather than the promised updates. Malicious programs can be unintentionally downloaded from untrustworthy sources, like: unofficial and free file-hosting websites, P2P sharing networks (BitTorrent, eMule, Gnutella, etc.) and other third party downloaders.

Threat Summary:
Name 0day0 virus
Threat Type Ransomware, Crypto Virus, Files locker
Encrypted Files Extension .0day0 (files are also appended with a unique ID and cyber criminals' email address)
Ransom Demanding Message Text presented in the pop-up window and FILES ENCRYPTED.txt
Cyber Criminal Contact day_0@aol.com and day_00@aol.com
Detection Names Avast (Win32:RansomX-gen [Ransom]), BitDefender (Trojan.Ransom.Crysis.E), ESET-NOD32 (A Variant Of Win32/Filecoder.Crysis.P), Kaspersky (Trojan-Ransom.Win32.Crusis.to), Full List Of Detections (VirusTotal)
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.
Distribution methods Infected email attachments (macros), torrent websites, malicious ads.
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.
Malware Removal (Windows)

To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Malwarebytes.
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How to protect yourself from ransomware infections?

Suspicious and/or irrelevant emails must not be opened, especially any attachments or links present in them - doing so can lead to a high-risk infection. It is recommended to always download from official and verified sources. It is just as important to activate and update products with tools/functions, provided by legitimate developers. Illegal activation tools ("cracks") and third party updaters are advised against use, due to such being often used to distribute malware. To protect device integrity and user safety, it is crucial to have a reputable anti-virus/anti-spyware suite installed. Furthermore, this software has to be kept up-to-date, used to run regular system scans and to remove detected/potential threats. If your computer is already infected with 0day0, we recommend running a scan with Malwarebytes for Windows to automatically eliminate this ransomware.

Text presented in 0day0 ransomware's pop-up window:

YOUR FILES ARE ENCRYPTED
Don't worry,you can return all your files!
If you want to restore them, follow this link:email day_0@aol.com YOUR ID 1E857D00
If you have not been answered via the link within 12 hours, write to us by e-mail:day_00@aol.com
Attention!
Do not rename encrypted files.
Do not try to decrypt your data using third party software, it may cause permanent data loss.
Decryption of your files with the help of third parties may cause increased price (they add their fee to our) or you can become a victim of a scam.

Screenshot of 0day0's text file ("FILES ENCRYPTED.txt"):

0day0 ransomware text file (FILES ENCRYPTED.txt)

Text presented in this file:

all your data has been locked us
You want to return?
write email day_0@aol.com or day_00@aol.com 

Screenshot of files encrypted by 0day0 (".0day0" extension):

Files encrypted by 0day0 ransomware (.0day0 extension)

0day0 ransomware removal:

Instant automatic malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Malwarebytes is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:
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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 0day0 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 0day0 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 0day0 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 0day0 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 0day0, 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 0day0 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 0day0 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 pcrisk.com since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats. Contact Tomas Meskauskas.

PCrisk security portal is brought by a company RCS LT. Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.

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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
0day0 virus QR code
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