How to remove GEROSAN ransomware (Virus Removal Guide)

If your pictures, documents, or files are encrypted with the Gerosan extension, then your computer is infected with the STOP (DJVU) ransomware.

The STOP (DJVU) ransomware encrypts the personal documents found on the victim’s computer, then displays a message which offers to decrypt the data if payment in Bitcoin is made. The instructions are placed on the victims desktop in the _readme.txt file.

Image: Gerosan ransomware virus
Image: Gerosan ransomware

If your files were encrypted using an offline key (How do I know if I was infected with an offline key?) there is a chance you can recover your files by using Michael Gillespie’s STOPDecrypter decryption tool. Unfortunately, in most cases, it’s not possible to recover the files encrypted by this ransomware because the private key which is needed to unlock the encrypted files is only available through the cybercriminals.

You can also try to search the below sites for updates about a decryption tool:

This guide was written to help you remove the infection itself from your computer, and if a 100% proven method to recover the encrypted files is found we will update this guide.

We cannot help you recover your files and we can only recommend that you use ShadowExplorer or free file recovery software to restore your documents.

1. How did the Gerosan ransomware get on my computer?

The Gerosan ransomware is distributed via spam email containing infected attachments or by exploiting vulnerabilities in the operating system and installed software.

Cyber-criminals spam out an email, with forged header information, tricking you into believing that it is from a shipping company like DHL or FedEx. The email tells you that they tried to deliver a package to you, but failed for some reason. Sometimes the emails claim to be notifications of a shipment you have made. Either way, you can’t resist being curious as to what the email is referring to – and open the attached file (or click on a link embedded inside the email). And with that, your computer is infected with the Gerosan ransomware.

Gerosan ransomware was also observed attacking victims by hacking open Remote Desktop Services (RDP) ports. The attackers scan for the systems running RDP (TCP port 3389) and then attempt to brute force the password for the systems.


2. What is Gerosan ransomware?

  • Ransomware family: STOP (DJVU) ransomware
  • Extensions: Gerosan
  • Ransomware note: _readme.txt
  • Ransom: From $490 to $980 (in Bitcoins)
  • Contact: gorentos@bitmessage.ch, stoneland@firemail.cc, or @datarestore on Telegram

The Gerosan ransomware restricts access to data by encrypting files. It then attempts to extort money from victims by asking for “ransom”, in the form of Bitcoin cryptocurrency, in exchange for access to data. This ransomware targets all versions of Windows including Windows 7, Windows 8 and Windows 10. When this ransomware is first installed on your computer it will create a random named executable in the %AppData% or %LocalAppData% folder. This executable will be launched and begin to scan all the drive letters on your computer for data files to encrypt.

Gerosan ransomware searches for files with certain file extensions to encrypt. The files it encrypts include important productivity documents and files such as .doc, .docx, .xls, .pdf, among others. When these files are detected, this infection will change the extension to Gerosan, so they are no longer able to be opened.

Files targeted are those commonly found on most PCs today; a list of file extensions for targeted files include:

.sql, .mp4, .7z, .rar, .m4a, .wma, .avi, .wmv, .csv, .d3dbsp, .zip, .sie, .sum, .ibank, .t13, .t12, .qdf, .gdb, .tax, .pkpass, .bc6, .bc7, .bkp, .qic, .bkf, .sidn, .sidd, .mddata, .itl, .itdb, .icxs, .hvpl, .hplg, .hkdb, .mdbackup, .syncdb, .gho, .cas, .svg, .map, .wmo, .itm, .sb, .fos, .mov, .vdf, .ztmp, .sis, .sid, .ncf, .menu, .layout, .dmp, .blob, .esm, .vcf, .vtf, .dazip, .fpk, .mlx, .kf, .iwd, .vpk, .tor, .psk, .rim, .w3x, .fsh, .ntl, .arch00, .lvl, .snx, .cfr, .ff, .vpp_pc, .lrf, .m2, .mcmeta, .vfs0, .mpqge, .kdb, .db0, .dba, .rofl, .hkx, .bar, .upk, .das, .iwi, .litemod, .asset, .forge, .ltx, .bsa, .apk, .re4, .sav, .lbf, .slm, .bik, .epk, .rgss3a, .pak, .big, wallet, .wotreplay, .xxx, .desc, .py, .m3u, .flv, .js, .css, .rb, .png, .jpeg, .txt, .p7c, .p7b, .p12, .pfx, .pem, .crt, .cer, .der, .x3f, .srw, .pef, .ptx, .r3d, .rw2, .rwl, .raw, .raf, .orf, .nrw, .mrwref, .mef, .erf, .kdc, .dcr, .cr2, .crw, .bay, .sr2, .srf, .arw, .3fr, .dng, .jpe, .jpg, .cdr, .indd, .ai, .eps, .pdf, .pdd, .psd, .dbf, .mdf, .wb2, .rtf, .wpd, .dxg, .xf, .dwg, .pst, .accdb, .mdb, .pptm, .pptx, .ppt, .xlk, .xlsb, .xlsm, .xlsx, .xls, .wps, .docm, .docx, .doc, .odb, .odc, .odm, .odp, .ods, .odt

Once your files are encrypted with the Gerosan extension, this ransomware will create the _readme.txt file ransom note in each folder that a file has been encrypted and on the Windows desktop. These files are located in every folder that a file was encrypted and contain the information on how to contact the cybercriminals and get your files back.

When the infection has finished scanning your computer it will also delete all of the Shadow Volume Copies that are on the affected computer. It does this so that you cannot use the shadow volume copies to restore your encrypted files.


3. Is my computer infected with Gerosan Ransomware?

When this ransomware infects your computer it will scan all the drive letters for targeted file types, encrypt them, and then append the Gerosan extension to them. Once these files are encrypted, they will no longer able to be opened by your normal programs. When this ransomware has finished encrypting the victim’s files, it will also display a ransom note that includes instructions on how to contact these cybercriminals (gorentos@bitmessage.ch or stoneland@firemail.cc).

This is the message that the Gerosan ransomware (_readme.txt) will display:

ATTENTION!

Don’t worry my friend, 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-oEUEuysYiZ
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:
stoneland@firemail.cc

Reserve e-mail address to contact us:
gorentos@bitmessage.ch

Support Telegram account:
@datarestore

Your personal ID:


4. Is it possible to decrypt files encrypted with the Gerosan ransomware?

If your file were encrypted using an offline key (How do I know if I was infected with an offline key?) there is a chance you can recover your files by using the STOPDecrypter decryption tool.

STOPDecrypter

Unfortunately, in most cases, it’s not possible to recover the files encrypted by this ransomware because the private key which is needed to unlock the encrypted file is only available through the cybercriminals.

There is no guarantee that if you pay the ransom your files will be recovered, furthermore, this will encourage these bad guys to continue and even expand their operations. We strongly recommend that you do not pay the ransom and instead address the law enforcement agency in your country to report this attack.


5. How to remove the Gerosan ransomware (Virus Removal Guide)

It’s important to understand that by starting the removal process you risk losing your files, as we cannot guarantee that you will be able to recover them. Malwarebytes and HitmanPro can detect and remove this infection, however, these programs cannot recover your documents, pictures, or files. Your files may be permanently compromised when trying to remove this infection or trying to recover the encrypted documents. We cannot be held responsible for losing your files or documents during this removal process.

STEP 1: Use Malwarebytes to remove Gerosan ransomware

Malwarebytes is one of the most popular and most used anti-malware software for Windows, and for good reasons. It is able to destroy many types of malware that other software tends to miss, without costing you absolutely nothing. When it comes to cleaning up an infected device, Malwarebytes has always been free and we recommend it as an essential tool in the fight against malware.

The first time you install Malwarebytes, you’re given a free 14-day trial of the premium edition, which includes preventative tools like real-time scanning and specific protection from ransomware. After two weeks, it automatically reverts to the basic free version that will detect and clean up malware infections only when you run a scan. It is important to note that Malwarebytes will run alongside antivirus software without conflicts.

  1. Download Malwarebytes.

    You can download Malwarebytes by clicking the link below.

    MALWAREBYTES DOWNLOAD LINK
    (The above link open a new page from where you can download Malwarebytes)
  2. Double-click on the Malwarebytes setup file.

    When Malwarebytes has finished downloading, double-click on the mb3-setup-consumer-x.x.x.xxxx.exe file to install Malwarebytes on your PC. In most cases, downloaded files are saved to the Downloads folder.

    Double-click on mb3-setup to install Malwarebytes Help
    You may be presented with a User Account Control pop-up asking if you want to allow Malwarebytes to make changes to your device. If this happens, you should click “Yes” to continue with the installation.
    Windows asking for permission to run the Malwarebytes installer - Help Guide

  3. Follow the on-screen prompts to install Malwarebytes.

    When the Malwarebytes installation begins, you will see the Malwarebytes Setup Wizard which will guide you through the installation process. To install Malwarebytes on your PC, click on the “Agree and Install” button.
    Malwarebytes Setup Screen - Help Guide
    Malwarebytes is installed on your PC - Help Guide

  4. Click on “Scan Now”.

    Once installed, Malwarebytes will automatically start and update the antivirus database. To perform a system scan, click on the “Scan Now” button.
    Start a scan with Malwarebytes

  5. Wait for the Malwarebytes scan to complete.

    Malwarebytes will now start scanning your computer for adware and other malicious programs. This process can take a few minutes, so we suggest you do something else and periodically check on the status of the scan to see when it is finished.
    Malwarebytes scanning PC for Gerosan malware

  6. Click on “Quarantine Selected”.

    When the scan has completed, you will be presented with a screen showing the malware infections that Malwarebytes has detected. To remove the malicious programs that Malwarebytes has found, click on the “Quarantine Selected” button.
    Click on the Quarantine Selected button to remove Gerosan virus

  7. Reboot your computer.

    Malwarebytes will now remove all the malicious files and registry keys that it has found. To complete the malware removal process, Malwarebytes may ask you to restart your computer.
    Malwarebytes requesting to restart computer to complete malware removal process - Help Guide
    When the malware removal process is complete, you can close Malwarebytes and continue with the rest of the instructions.


STEP 2: Use HitmanPro to scan for malware and unwanted programs

HitmanPro is a second opinion scanner that takes a unique cloud-based approach to malware scanning. HitmanPro scans the behavior of active files and also files in locations where malware normally resides for suspicious activity. If it finds a suspicious file that’s not already known, HitmanPro sends it to their clouds to be scanned by two of the best antivirus engines today, which are Bitdefender and Kaspersky.

Although HitmanPro is shareware and costs $24.95 for 1 year on 1 PC, there is actually no limit in scanning. The limitation only kicks in when there is a need to remove or quarantine detected malware by HitmanPro on your system and by then, you can activate the one time 30-day trial to enable the cleanup.

  1. Download HitmanPro.

    You can download HitmanPro by clicking the link below.

    HITMANPRO DOWNLOAD LINK
    (The above link will open a new web page from where you can download HitmanPro)
  2. Install HitmanPro.

    When HitmanPro has finished downloading, double-click on “hitmanpro.exe” (for 32-bit versions of Windows) or “hitmanpro_x64.exe” (for 64-bit versions of Windows) to install this program on your PC. In most cases, downloaded files are saved to the Downloads folder.

    Double-click on the HitmanPro setup file - Help Guide
    You may be presented with a User Account Control pop-up asking if you want to allow HitmanPro to make changes to your device. If this happens, you should click “Yes” to continue with the installation.

    Windows asking for permissions to run the HitmanPro setup file - Help Guide

  3. Follow the on-screen prompts.

    When HitmanPro starts you will be presented with the start screen as shown below. Click on the “Next” button to perform a system scan.

    Click Next to install HitmanPro

    HitmanPro final installer screen

  4. Wait for the HitmanPro scan to complete.

    HitmanPro will now begin to scan your computer for malicious programs. This process will take a few minutes.
    HitmanPro while scanning for malware - Help Guide

  5. Click on “Next”.

    When HitmanPro has finished the scan, it will display a list of all the malware that the program has found. Click on the “Next” button to remove the malicious programs.
    HitmanPro scan summary. Click Next to remove Gerosan virus

  6. Click on “Activate free license”.

    Click on the “Activate free license” button to begin the free 30 days trial and remove all the malicious files from your PC.
    Activate the free HitmanPro license keyEnter your email to complete the HitmanPro activation - Help Guide
    When the process is complete, you can close HitmanPro and continue with the rest of the instructions.

STEP 3: Restore the files encrypted by Gerosan ransomware with recovery software

In some cases, it may be possible to recover previous versions of the encrypted files using Gerosan Restore or other recovery software used to obtain “shadow copies” of files.

Option 1: Restore your files encrypted by Gerosan ransomware with ShadowExplorer

The Gerosan ransomware will attempt to delete all shadow copies when you first start any executable on your computer after becoming infected. Thankfully, the infection is not always able to remove the shadow copies, so you should continue to try restoring your files using this method.

  1. You can download ShadowExplorer from the below link:
    SHADOW EXPLORER DOWNLOAD LINK (This link will open a new web page from where you can download “ShadowExplorer”)
  2. Once you have downloaded and installed ShadowExplorer, you can follow the below video guide on how to restore your files while using this program.

Option 2: Restore your files encrypted with the Gerosan extension with File Recovery Software

When the files are encrypted, this ransomware first makes a copy of them, encrypts the copy, and then deletes the original. Because of this, there might be a small chance we can use file recovery software to restore the deleted files.


How to prevent your computer from becoming infected by Gerosan ransomware

To protect your computer from the Gerosan ransomware, you should always have an antivirus installed on your computer and always have a backup for your personal documents. As an extra protection method, you can use programs called HitmanPro.Alert which will prevent any file-encrypting malware from running.


Your computer should now be free of the Gerosan ransomware infection. If you are still experiencing problems while trying to remove Gerosans ransomware from your computer, please do one of the following:

How to Stay Safe Online

Here are 10 basic security tips to help you avoid malware and protect your device:

  1. Use a good antivirus and keep it up-to-date.

    Shield Guide

    It's essential to use a good quality antivirus and keep it up-to-date to stay ahead of the latest cyber threats. We are huge fans of Malwarebytes Premium and use it on all of our devices, including Windows and Mac computers as well as our mobile devices. Malwarebytes sits beside your traditional antivirus, filling in any gaps in its defenses, and providing extra protection against sneakier security threats.

  2. Keep software and operating systems up-to-date.

    updates-guide

    Keep your operating system and apps up to date. Whenever an update is released for your device, download and install it right away. These updates often include security fixes, vulnerability patches, and other necessary maintenance.

  3. Be careful when installing programs and apps.

    install guide

    Pay close attention to installation screens and license agreements when installing software. Custom or advanced installation options will often disclose any third-party software that is also being installed. Take great care in every stage of the process and make sure you know what it is you're agreeing to before you click "Next."

  4. Install an ad blocker.

    Ad Blocker

    Use a browser-based content blocker, like AdGuard. Content blockers help stop malicious ads, Trojans, phishing, and other undesirable content that an antivirus product alone may not stop.

  5. Be careful what you download.

    Trojan Horse

    A top goal of cybercriminals is to trick you into downloading malware—programs or apps that carry malware or try to steal information. This malware can be disguised as an app: anything from a popular game to something that checks traffic or the weather.

  6. Be alert for people trying to trick you.

    warning sign

    Whether it's your email, phone, messenger, or other applications, always be alert and on guard for someone trying to trick you into clicking on links or replying to messages. Remember that it's easy to spoof phone numbers, so a familiar name or number doesn't make messages more trustworthy.

  7. Back up your data.

    backup sign

    Back up your data frequently and check that your backup data can be restored. You can do this manually on an external HDD/USB stick, or automatically using backup software. This is also the best way to counter ransomware. Never connect the backup drive to a computer if you suspect that the computer is infected with malware.

  8. Choose strong passwords.

    lock sign

    Use strong and unique passwords for each of your accounts. Avoid using personal information or easily guessable words in your passwords. Enable two-factor authentication (2FA) on your accounts whenever possible.

  9. Be careful where you click.

    cursor sign

    Be cautious when clicking on links or downloading attachments from unknown sources. These could potentially contain malware or phishing scams.

  10. Don't use pirated software.

    Shady Guide

    Avoid using Peer-to-Peer (P2P) file-sharing programs, keygens, cracks, and other pirated software that can often compromise your data, privacy, or both.

To avoid potential dangers on the internet, it's important to follow these 10 basic safety rules. By doing so, you can protect yourself from many of the unpleasant surprises that can arise when using the web.

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