Djvu VirusRansomwareRemoval Guide

Cadq Virus Removal Guide (+Decrypt .cadq files)

Cadq Virus – Details

Cadq is a harmful software functioning as typical ransomware. Michael Gillespie, the popular virus researcher, very first found this new name in the DJVU ransomware family.

Cadq was created for the sole purpose to encrypt all popular file types. Realistically, as soon as the encryption is successfully accomplished, the users are unable to get access to them. Cadq ransomware includes its own “.cadq” extension to all the encrypted files. For example, the file “price_list.xls”, as soon as encrypted by Cadq, will be titled as “price_list.xls.cadq”. As soon as the file encryption is achieved, Cadq puts its own unique text file (_readme.txt) into all the folders that keep the encrypted files.

The alert stated by the text file requesting for the random os really comparable to the alerts given by other ransomware hazards belonging to the DJVU family. The caution generally indicates that the files have been secured and the only option to get access to it is to use a distinct standalone key. Regretfully, this declaration is definitely true.

The method to encrypt the files utilized by Cadq is not completely looked into. However, there is no doubt that each computer system owner may be released a special decryption key, which is definitely special. It is incredibly tough to recuperate the data without a suitable key in location.

“Don’t worry, you can return all your files!”, from text file message:

Don't worry, you can return all your files! virus

One more peculiarity of the Cadq virus is that the users are not able to get access to the key. The decrypting key is hosted on a special server under complete control by the crooks who have launched the Cadq ransomware into the web. In order to get the key and restore the essential information, the users are informed to get in touch with the frauds through email or by telegram and to pay the ransom in the quantity of $980.

The message also states that individuals need to get in touch with the Cadq authors within 72 hours of the moment of the data file encryption. The alert suggests that by doing so individuals will get a 50% discount, for that reason, the ransom quantity drops down to $490.

No matter what the amount of the ransom is, we highly recommend that you do not pay the ransom. There is no guarantee that these online crooks will keep their pledges, so they might not care at all what the victims feel about the encryption, even when the amount of the ransom is received into their accounts. For this reason, paying ransom typically does not result in effective recovery. So, the users might simply lose their money for nothing.

Likewise, we urge you not to get in touch with the frauds as they advise. Do not move money into their wallets. There are no applications that might break the Cadq virus or restore the information for free. For that reason, the only right decision is to bring back the data from possible backups (if available).

Virus Summary

NameCadq Ransomware
File Extensioncadq
Short DescriptionThe ransomware encrypts all the data stored on your system and requires a ransom to be paid on your part supposedly to recover your important files.
SymptomsFile encryption by the ransomware is performed by means of the AES-256 algorithm (CFB mode) encryption algorithm. Once the encryption is completed, the ransomware adds its special .cadq extension to all the files modified by it.
Distribution MethodAdware bundles and software cracks
Similar InfectionsYgkz, Cosd, Plam
Cadq Removal Tool   GridinSoft Anti-Malware
Cadq Decryption Tool   Emsisoft Djvu Decryptor

Do not forget that the Web is now loaded with infections comparable to the Cadq ransomware. For instance, this specific risk is basically identical to Brusaf and other ransomware-type infections. These harmful energies have been established in order to secure the essential data and express the need for the users to pay the ransom. All these infections use the similar algorithm to generate the specific key for effective files decryption.

Unless the Cadq ransomware is still under the advancement procedure or has got some hidden bugs, it is not possible to bring back the information by hand. Hence, the only working service to avoid the loss of your important data is to frequently maintain updated backups of all your crucial documents.

Another essential piece of suggestions is to store the backups on unique storage not connected to your primary PC. For example, you may store it on the USB Flash Drive, or some external disk drive, or by using the cloud data storage services. Keeping the backups on your system drive is really risky, considering that the backup might likewise be encrypted by the Cadq .

Leaks for the Cadq ransomware attack.

Cadq uses many courses to infiltrate the susceptible computers. It is not specific what specific method was used in your case, nevertheless, the invasion might happen via the following channels:

  • bundling with third-party programs, primarily free apps;
  • spam emails from the unidentified senders;
  • sites supplying complimentary hosting;
  • P2P (peer-to-peer) torrent software.

There are times when the Cadq virus might disguise itself as some real application, for instance, through the misleading alerts requiring installation of some software application update. This is the most common trick utilized by the frauds to inject the Cadq ransomware files into the system. This way users partially participate in its setup, without clearly understanding the danger.

Additionally, the frauds may send unsolicited spam email with challenging informs motivating the people to open suspicious accessories or click on some download links, for instance, those motivating the people to open particular pictures, text files, tax files and other info.

No doubt, opening these files or clicking the malicious links may essentially damage the system. Fake Media Player upgrade alerts may lead to the Cadq ransomware seepage. Likewise, downloading the broken software application may in addition contain the ransomware installer. The last however not the least, setup of Cadq may take place through some Trojan horses that may be set up stealthily into the system and without the user’s direct authorization or even approval.

Preventing the Cadq ransomware attack.

Naturally, there is no absolute assurance that your computer will be constantly devoid of any malware attacks, nevertheless, we want to share some helpful tips with you to make it much safer. Make certain to pay very close attention while browsing the web and specifically while downloading cost-free programs. Do not open any dubious e-mail attachments, especially if the sender is not understood to you.

Do not forget that particular freeware installer may likewise consist of some other extra apps in the bundle. These additional applications may be really harmful. It is of utmost value to keep your anti-virus software application and your operating system in basic to be always properly upgraded.

It is quite rational that downloading pirated programs is unlawful, nevertheless, in addition, such unapproved programs use may likewise bring severe damage to your system. Thus, do not download any split programs. Plus, the truth that your current anti-virus did not protect the system from the Cadq ransomware is a great reason for you to reconsider your options and change to another program that can render the securing functions on a better level.

Below please find the quotation from the Cadq text file:

 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: 

 Our Telegram account:

Screenshot of files with “.cadq” extension added by the virus:”

Cadq Ransomware - encrypt files with .cadq extension

Use GridinSoft Anti-Malware to remove Cadq ransomware from your computer

1.Download GridinSoft Anti-Malware.

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

  GridinSoft Anti-Malware

2. Double-click on the setup file.

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

3. Press Install button for run GridinSoft Anti-Malware.

GridinSoft Anti-Malware Install

3.Once installed, GridinSoft Anti-Malware will automatically run.

GridinSoft Anti-Malware  Start

4. Wait for the GridinSoft Anti-Malware scan to complete.

GridinSoft Anti-Malware will automatically start scanning your computer for Win Speedup 2018 and other malicious programs. This process can take a 20-30 minutes, so we suggest you periodically check on the status of the scan process.
GridinSoft Anti-Malware Scan

5. 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

Use Emsisoft Decryptor for restore cadq files

You can download Emsisoft Decryptor by clicking the button below:

  Emsisoft Decryptor

  1. Run the decryptor as an administrator. The license terms will show up, which you have to agree to by clicking the “Yes” button.
  2. Once the license terms are accepted, the primary decryptor user interface opens.
  3. By default, the decryptor will pre-populate the locations to decrypt with the currently connected drives and network drives. Additional locations can be added using the Add” button.
  4. Decryptors typically offer various options depending on the particular malware family. The available options are located in the Options tab and can be enabled or disabled there. You can find a detailed list of the available Options below.
  5. After you have added all the locations you want to decrypt to the list, click the “Decrypt” button to start the decryption process. The screen will switch to a status view, informing you about the current process and decryption status of your files
  6. The decryptor will inform you once the decryption process is finished. If you require the report for your personal records, you can save it by clicking the “Save log” button. You can also copy it straight to your clipboard to paste it into emails or forum posts if you are asked to.
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Daniel Zimmermann

Daniel Zimmermann has been writing on security and malware subjects for many years and has been working in the security industry for over 10 years. Daniel was educated at the Saarland University in Saarbrücken, Germany and currently lives in New York.

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