Lisp Virus Removal Guide (+Decrypt .lisp files)

Lisp – General Info

Lisp is a malicious software application working as typical ransomware. Michael Gillespie, the well-known malware researcher, first discovered this new name in the DJVU ransomware family.

Lisp was developed for the sole function to encrypt all popular file types. Rationally, as soon as the encryption is successfully achieved, the users are unable to get access to them. Lisp virus includes its own “.lisp” to all the encrypted data. For example, the file “price_list.xls”, when modified by Lisp, will be titled as “price_list.xls.lisp”. When the encryption is accomplished, Lisp puts its own distinct text document (_readme.txt) into all the folders that keep the encrypted files.

The message specified by text file requesting the random os really comparable to the notices provided by other ransomware dangers coming from the DJVU family. The warning generally indicates that the information has been encrypted and the only solution to get access to it is to use an unique standalone key. Regretfully, this declaration is definitely real.

The technique to encrypt the files used by Lisp is not completely researched. However, there is no doubt that each computer system owner may be issued an unique decryption key, which is definitely distinct. It is incredibly tough to recuperate the information without the appropriate key in location.

“Don’t worry, you can return all your files!”, from _readme.txt message:

message from Lisp virus

One more peculiarity of the Lisp infection is that the users are unable to get access to the key. The decrypting key is hosted on a special server under the total control by the crooks who have introduced the Lisp ransomware into the internet. In order to get the key and restore the essential data, the users are informed to get in touch with the scams by means of e-mail or by telegram and to pay the ransom in the quantity of $980.

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

No matter what the quantity of the ransom is, we highly encourage that you do not pay the ransom. There is no warranty that these online scoundrels will keep their promises, so they might not care at all what the victims feel about the encryption, even when the amount of the ransom is gotten into their accounts. Thus, paying ransom often does not lead to a successful recovery. So, the users might just lose their money for nothing.

Likewise, we advise you not to get in touch with the frauds as they advise. Do not transfer cash into their wallets. There are no applications that could split the Lisp virus or bring back the data at no charge. Therefore, the only right decision is to bring back the information from possible backups (if offered).

Virus Summary

NameLisp Ransomware
File Extensionlisp
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 .lisp extension to all the files modified by it.
Distribution MethodAdware bundles and software cracks
Similar InfectionsSglh, Epor, Vvoa
Lisp Removal Tool   GridinSoft Anti-Malware
Lisp Decryption Tool   Emsisoft Djvu Decryptor

Do not forget that the Web is now loaded with infections similar to the Lisp virus. For instance, this particular danger is generally identical to Brusaf and other ransomware-type infections. These damaging utilities have actually been developed in order to secure the important information and express the need for the users to pay the ransom. All these infections utilize the identical algorithm to produce the specific key for effective information decryption.

Unless the Lisp ransomware is still under the advancement procedure or has actually got some concealed bugs, it is not possible to restore the data manually. Thus, the only working service to avoid the loss of your essential information is to routinely preserve up-to-date backups of all your essential documents.

Another crucial piece of guidance is to keep the backups on special storage not linked to your primary PC. For instance, you may store it on the USB Flash Drive, or some external drive, or by using the cloud data storage services. Keeping the backups on your routine drive is really dangerous, considering that the backup might also be secured by the Lisp .

Leakages for the Lisp ransomware attack.

Lisp uses numerous paths to infiltrate the vulnerable computer systems. It is not certain what particular technique was utilized in your case, nevertheless, the intrusion may take place through the following channels:

  • bundling with third-party programs, mainly free software;
  • spam e-mails from the unknown senders;
  • sites offering complimentary hosting;
  • P2P (peer-to-peer) torrent downloads.

There are times when the Lisp virus may disguise itself as some genuine application, for example, through the misleading informs demanding installation of some software update. This is the most typical technique used by the frauds to inject the Lisp infection files into the system. By doing this users partially participate in its setup, without plainly understanding the danger.

Furthermore, the frauds might send out unsolicited spam email with difficult signals encouraging the people to open dubious accessories or click some download links, for example, those motivating the people to open specific images, text files, tax documents and other info.

No doubt, opening these files or clicking the destructive links may essentially damage the system. Fake Adobe Flash Player update alerts may cause the Lisp ransomware seepage. Likewise, downloading the split software application may in addition contain the ransomware installer. The last but not the least, installation of Lisp may occur through some Trojan horses that might be set up stealthily into the system and without the user’s direct approval or even approval.

Avoiding the Lisp injection.

Obviously, there is no absolute assurance that your computer will be constantly devoid of any malware attacks, nevertheless, we wish to share some useful pointers with you to make it safer. Make sure to pay very very close attention while searching the web and specifically while getting cost-free programs. Do not open any dubious email attachments, particularly if the sender is not understood to you.

Do not forget that particular freeware installer may also consist of some other additional apps in the package. These extra applications might be really destructive. It is of utmost importance to keep your anti-virus software and your os in basic to be constantly properly updated.

It is rather sensible that downloading cracked apps is prohibited, nevertheless, furthermore, such unapproved programs usage might likewise bring serious damage to your system. Thus, do not download any split programs. Plus, the reality that your current anti-virus did not protect the system from the Lisp ransomware is a great reason for you to reconsider your choices and change to another program that can render the protecting functions on a better level.

Below please find the quotation from the Lisp 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 “.lisp” extension added by the ransomware:”

Lisp Ransomware - encrypt files with .lisp extension

Use GridinSoft Anti-Malware to remove Lisp 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 lisp files

You can get 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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About 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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