DERP VIRUS – Restore .derp files (Updated 25 Nov)

Written by Brendan Smith
Derp is a DJVU family of ransomware-type infections. The virus encrypts your private files (video, photos, documents). The infected files can be tracked by specific “.derp” extension. So, you can’t obtain access to them at all.
GridinSoft Anti-Malware Review
It is better to prevent, than repair and repent!
When we talk about the intrusion of unfamiliar programs into your computer’s work, the proverb “Forewarned is forearmed” describes the situation as accurately as possible. Gridinsoft Anti-Malware is exactly the tool that is always useful to have in your armory: fast, efficient, up-to-date. It is appropriate to use it as an emergency help at the slightest suspicion of infection.
Gridinsoft Anti-Malware 6-day trial available.
EULA | Privacy Policy | 10% Off Coupon
Subscribe to our Telegram channel to be the first to know about news and our exclusive materials on information security.
In this tutorial I will try to help you remove Derp ransomware without any payment. As bonus I will assist you in decoding your crypted files.

What is “Derp”?

Derp can be correctly identify as a ransomware-type infection.
Ransomware is a specific kind of virus that crypted your documents and then forces you to pay for them. DJVU (aka STOP) ransomware family was first revealed and discovered by virus analyst Michael Gillespie1.

Here is a details for the Derp infection:

Ransomware familyDJVU/STOP ransomware
Extension.derp
Ransomware note_readme.txt
DetectionTrojan-PSW.Win32.Azorult.agkp, Win32/Kryptik.GYXR, Trojan-Ransom.Win32.Shade.qjq
SymptomsMost of your files (photos, videos, documents) have a .derp extension and you can’t open it
Fix ToolSee If Your System Has Been Affected by .derp file virus

Derp is similar to other ransomware like: Coot, Nols, Is. It crypted all popular file types. Hence, users cannot work with the your documents or photos. Derp adds its own “.derp” extension into all files. For example, the file “video.avi”, will be changed into “video.avi.derp”. As soon as the encryption is successfully accomplished, Derp generates a special text file “_readme.txt” and puts it into all folders that contain the modified files.

This text asking payment is for get files back via decryption key:

Derp virus message

The scary alert demanding from users to pay the ransom to decrypt the encoded data contains these frustrating warnings

The cryptography algorithm used by Derp is AES-556. So, if your files got encrypted with a specific decryption key, which is totally and there are no other copies. The sad reality is that it is impossible to recover the information without the unique key available.

In case if Derp worked in online mode, it is impossible for you to gain access to the AES-556 key. It is stored on a remote server owned by the frauds who distibute the Derp ransomware.

For receiving decryption key the payment should be $980. To obtain the payment details the victims are encouraged by the message to contact the frauds by email (gorentos@bitmessage.ch), or via Telegram.

Do not pay for Derp!

Please, try to use the available backups, or STOPDecrypter tool

_readme.txt file also indicates that the computer owners must get in touch with the Derp representatives during 72 hours starting from the moment of files where crypted. On the condition of getting in touch within 72 hours users will be granted a 50% rebate, thus the ransom amount will be minimized down to $490). Yet, stay away from paying the ransom!

I strongly advise that you do not contact these frauds and do not pay. The one of the most real working solution to recover the lost data – just using the available backups, or use STOPDecrypter tool.

The peculiarity of all such viruses apply a similar set of actions for generating the unique decryption key to recover the ciphered data.

Thus, unless the ransomware is still under the stage of development or possesses with some hard-to-track flaws, manually recovering the ciphered data is a thing you can’t really perform. The only solution to prevent the loss of your valuable data is to regularly make backups of your crucial files.

Note that even if you do maintain such backups regularly, they ought to be put into a specific location without loitering, not being connected to your main workstation.

For instance, the backup may be kept on the USB flash drive or some alternative external hard drive storage. Optionally, you may refer to the help of online (cloud) information storage.

Needless to mention, when you maintain your backup data on your common device, it may be similarly ciphered as well as other data.

For this reason, locating the backup on your main device is surely not a wise idea.

How I was infected?

Derp has a various methods to built into your system. But it doesn’t really matter what way was used in your case.

Derp infection attack

Derp ransomware attack following a successful phishing attempt.

Nevertheless, these are the common leaks through which it may be injected into your PC:

  • hidden installation along with other apps, especially the utilities that work as freeware or shareware;
  • dubious link in spam emails leading to the Derp installer
  • online free hosting resources;
  • using illegal peer-to-peer (P2P) resources for downloading pirated software.

There were cases when the Derp virus was disguised as some legitimate tool, for example, in the messages demanding to initiate some unwanted software or browser updates. This is typically the way how some online frauds aim to force you into installing the Derp ransomware manually, by actually making you directly participate in this process.

Surely, the bogus update alert will not indicate that you are going to actually inject the Derp ransomware. This installation will be concealed under some alert mentioning that allegedly you should update Adobe Flash Player or some other dubious program whatsoever.

Of course, the cracked apps represent the damage too. Using P2P is both illegal and may result in the injection of serious malware, including the Derp ransomware.

To sum up, what can you do to avoid the injection of the Derp ransomware into your device? Even though there is no 100% guarantee to prevent your PC from getting damaged, there are certain tips I want to give you to prevent the Derp penetration. You must be cautious while installing free software today.

Make sure you always read what the installers offer in addition to the main free program. Stay away from opening dubious email attachments. Do not open files from the unknown addressees. Of course, your current security program must be always updated.

The malware does not speak openly about itself. It will not be mentioned in the list of your available programs. However, it will be masked under some malicious process running regularly in the background, starting from the moment when you launch your computer.


The message by the Derp ransomware states the following frustrating information:

ATTENTION!
 
 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:
 https://we.tl/t-2P5WrE5b9f
 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:
 gorentos@bitmessage.ch
  
 Reserve e-mail address to contact us:
 gorentos2@firemail.cc
  
 Our Telegram account:
 @datarestore
 Mark Data Restore
 
Your personal ID:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

The image below gives a clear vision of how the files with “.derp” extension look like:

Derp Virus - crypted .derp files

Example of crypted .derp files

How to remove Derp virus?

In addition to encode a victim’s files, the Derp virus has also started to install the Azorult Spyware on computer to steal account credentials, cryptocurrency wallets, desktop files, and more.
Reasons why I would recommend GridinSoft2

The is an excellent way to deal with recognizing and removing threats – using Gridinsoft Anti-Malware. This program will scan your PC, find and neutralize all suspicious processes3.

Download Removal Tool.

You can download GridinSoft Anti-Malware by clicking the button below:

Run the setup file.

When setup file has finished downloading, double-click on the install-antimalware-fix.exe file to install GridinSoft Anti-Malware on your system.

Run Setup.exe

An User Account Control asking you about to allow GridinSoft Anti-Malware to make changes to your device. So, you should click “Yes” to continue with the installation.

GridinSoft Anti-Malware Setup

Press “Install” button.

GridinSoft Anti-Malware Install

Once installed, Anti-Malware will automatically run.

GridinSoft Anti-Malware Splash-Screen

Wait for the Anti-Malware scan to complete.

GridinSoft Anti-Malware will automatically start scanning your PC for Derp infections and other malicious programs. This process can take a 20-30 minutes, so I suggest you periodically check on the status of the scan process.

GridinSoft Anti-Malware Scanning

Click on “Clean Now”.

When the scan has completed, you will see the list of infections that GridinSoft Anti-Malware has detected. To remove them click on the “Clean Now” button in right corner.

GridinSoft Anti-Malware Scan Result

How to decrypt .derp files?

Updated 25 Nov 2019

Emsisoft Decryptor has obtained and uploaded to server OFFLINE KEYS for the following new STOP (Djvu) variant:

.gero, .hese, .seto, .peta, .moka, .meds, .kvag, .domn, .karl, .nesa, .noos, .kuub, .reco, .bora, .nols, .werd, .coot, .derp, .meka, .mosk, .lokf, .peet, .mbed, .kodg

Download and run decryption tool.

Start downloading the decryption tool.

Make sure to launch the decryption utility as an administrator. You need to agree with the license terms that will come up. For this purpose, click on the “Yes” button:

Emsisoft Decryptor - license terms

As soon as you accept the license terms, the main decryptor user interface comes up:

Emsisoft Decryptor - user interface

Select folders for decryption.

Based on the default settings, the decryptor will automatically populate the available locations in order to decrypt the currently available drives (the connected ones), including the network drives. Extra (optional) locations can be selected with the help of the “Add” button.

Decryptors normally suggest several options considering the specific malware family. The currently possible options are presented in the Options tab and can be activated or deactivated there. You may locate a detailed list of the currently active Options below.

Click on the “Decrypt” button.

As soon as yo add all the desired locations for decryption into the list, click on the “Decrypt” button in order to initiate the decryption procedure.

Note that the main screen may turn you to a status view, letting you know of the active process and the decryption statistics of your data:

Emsisoft Decryptor - the decryption statistics

The decryptor will notify you as soon as the decryption procedure is completed. If you need the report for your personal papers, you can save it by choosing the “Save log” button. Note that it is also possible to copy it directly to your clipboard and to paste it into emails or forum messages if you need to do so.

What the next?

If the guide doesn’t help you to remove Derp virus, please download the GridinSoft Anti-Malware that I recommended. Also, you can always ask me in the comments for getting help.

Sending
User Review
0 (0 votes)
Comments Rating 0 (0 reviews)

References

  1. Twitter: https://twitter.com/demonslay335
  2. GridinSoft Anti-Malware Review from HowToFix site: https://howtofix.guide/gridinsoft-anti-malware/
  3. More information about GridinSoft products: https://gridinsoft.com/comparison

About the author

Brendan Smith

I'm Brendan Smith, a passionate journalist, researcher, and web content developer. With a keen interest in computer technology and security, I specialize in delivering high-quality content that educates and empowers readers in navigating the digital landscape.

With a focus on computer technology and security, I am committed to sharing my knowledge and insights to help individuals and organizations protect themselves in the digital age. My expertise in cybersecurity principles, data privacy, and best practices allows me to provide practical tips and advice that readers can implement to enhance their online security.

18 Comments

  1. Juan Sanchis October 31, 2019
  2. Anupama Engineer November 4, 2019
    • Brendan Smith November 26, 2019
  3. rene November 27, 2019
    • Brendan Smith November 30, 2019
  4. Saad December 2, 2019
  5. Leonard Manalili December 4, 2019
  6. Aboozar December 27, 2019
    • ayoub March 16, 2020
  7. hieu January 21, 2020
  8. Mal January 30, 2020
  9. Gulzar April 5, 2020
  10. hieu April 27, 2020
  11. Phạm Quốc Hiệu August 14, 2020
  12. andriar mikahrun June 10, 2021
  13. jorge November 14, 2021

Leave a Reply

Sending