Dangerous Ransomware

Also Known As: Dangerous virus
Distribution: Low
Damage level: Severe

Dangerous ransomware removal instructions

What is Dangerous?

Discovered by Michael Gillespie, Dangerous is a ransomware-type virus that stealthily infiltrates the system and encrypts most stored data. During encryption, Dangerous appends filenames with the ".wtf" extension. For example, "sample.jpg" is renamed to "sample.jpg.wtf". From this point, files become unusable. Following successful encryption, Dangerous places a copy of the "HOWTODECRYPTFILES.html" file in all existing folders.

The new HTML file contains a text message informing victims of the current situation and encouraging them to contact cyber criminals (developers of Dangerous). Users then supposedly receive further decryption instructions. It is currently unknown whether Dangerous uses symmetric or asymmetric cryptography, however, in any case, decryption requires a unique key. Developers store these keys on a remote server and users are encouraged to pay ransoms to receive them. The cost for Dangerous ransomware decryption is currently unconfirmed, however, cyber criminals commonly demand $500-$1500 in Bitcoins. No matter what the cost, never pay any ransom. Research shows that cyber criminals commonly ignore victims, once ransoms are paid. Paying will deliver no positive result and you will be scammed. Ignore all requests to contact these people or pay any ransom. Unfortunately, there are no tools capable of restoring files encrypted by Dangerous. Therefore, the only solution is to restore everything from a backup.

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

Dangerous decrypt instructions

The Internet is full of ransomware-type viruses similar to Dangerous (for example, File-Locker, Cyclone, ExecutionerPlus, and Halloware). Note that, although these viruses are developed by different cyber criminals, they have identical behavior - all encrypt data and make ransom demands. There are just two major differences: 1) size of ransom, and; 2) type of encryption algorithm used. Unfortunately, most of these viruses employ algorithms that generate unique encryption/decryption keys (e.g., RSA, AES, etc.) Therefore, unless the malware is not fully developed or has certain bugs/flaws (e.g., the key is hard-coded, stored locally, etc.), restoring files manually is impossible. Dangerous and other ransomware-type viruses are one of the main reasons for keeping regular data backups, however, note that backup files must be stored in a type of external storage or remote server (e.g., Cloud). If not, the backups are also encrypted.

How did ransomware infect my computer?

To proliferate ransomware, developers employ spam emails (malicious attachments), peer-to-peer (P2P) networks (torrents, eMule, etc.), third party software download sources (free file hosting websites, freeware download websites, so forth), fake update tools, and trojans. Infectious attachments usually (but not necessarily) come in the format of JavaScript files or MS Office documents. Once opened, these files download and install malware, whilst P2P networks and other unofficial download sources proliferate viruses by presenting them as legitimate software. Users are often tricked into downloading and installing malware. Fake software updaters infect the system by exploiting outdated software bugs/flaws. Trojans simply open "gates" for malware to infiltrate the system.

Threat Summary:
NameDangerous virus
Threat TypeRansomware, Crypto Virus, Files locker
SymptomsCan't open files stored on your computer, previously functional files now have a different extension, for example my.docx.locked. A ransom demanding message is displayed on your desktop. Cyber criminals are asking to pay a ransom (usually in bitcoins) to unlock your files.
Distribution methodsInfected email attachments (macros), torrent websites, malicious ads.
DamageAll 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 Dangerous virus our malware researchers recommend scanning your computer with Spyhunter.
▼ Download Spyhunter
Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

How to protect yourself from ransomware infections?

The main reasons for computer infections are poor knowledge and careless behavior. The key to safety is caution. Therefore, pay close attention when browsing the Internet. Attachments received from suspicious email addresses should never be opened. In fact, delete these emails without reading. Furthermore, download your software only from official/certified sources and, preferably, using a direct download link. Third party downloaders/installers often include rogue programs. Therefore, never use these tools. Keep installed applications up-to-date and use a legitimate anti-virus/anti-spyware suite, however, since criminals use fake updaters to proliferate malware, software should be updated using implemented functions or tools provided by the official developer.

Text presented in Dangerous ransomware HTML file ("HOWTODECRYPTFILES.html"):

Dangerous Ransomware
To decrypt the files, you need to purchase special software Dangerous decryptor
Restore the data, follow the instructions!
You can learn more / request
e-mail: dd.coala@protonmail.com
You can learn more/questions in the chat:
hxxp://kuysqebjbttaxmq2.onion.to (not need Tor)
hxxps://kuysqebjbttaxmq2.onion.cab (not need Tor)
hxxp://kuysqebjbttaxmq2.onion/ (need Tor)
You can learn more problem out bitmessage:
hxxps://bitmsg.me/ BM-2cTFScArDZfPNYbefeDn1RJL44NkvuVPrU

If the resource is unavailable for a long time to install and use the terms of reference of the browser:
1. + Start the Internet browser
2. + Type or copy the address https://www.torproject.org/download/download-easy.html in the address bar of your browser and press key ENTER
3. + On the website you will be prompted to download the Tor browser, download and install it. To work.
4. + Connection, click "connect" (using English version)
5. + After connecting, open a normal window Tor-browser
6. + Type or copy the address http://kuysqebjbttaxmq2.onion/ in the address bar of Tor-browser and press key ENTER
7. + Wait for the download site
+ If you have any problems with installation or usage, please visit the video:
8. Your personal identification ID:[redacted]

Screenshot of files encrypted by Dangerous (".wtf" extension):

Files encrypted by Dangerous

Dangerous ransomware removal:

Instant automatic removal of Dangerous 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 Dangerous 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 Dangerous 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 Dangerous 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 Dangerous 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 Dangerous 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 Dangerous, 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 Dangerous 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 as well as 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 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 Dangerous 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 virus and spyware activity level today:

Medium threat activity

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

QR Code
Dangerous virus QR code
A QR code (Quick Response Code) is a machine-readable code which stores URLs and other information. This code can be read using a camera on a smartphone or a tablet. Scan this QR code to have an easy access removal guide of Dangerous virus on your mobile device.
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Platform: Windows

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