Iisa ransomware (virus) - Decryption Methods Included

Iisa virus Removal Guide

What is Iisa ransomware?

Iisa ransomware is the cryptovirus that asks for payment and promises to recover files after the transfer

Iisa ransomwareThe infection is causing issues with data and demands the payment

Iisa virus is an extortion-based program from cybercriminals who are focused on money demands. The encryption process is used to create issues with the machine, so once the ransom note appears on the screen, victims get straight to payment and think that data can be restored. Unfortunately, files marked with .iisa appendix and made useless, so the payments can be gathered. None of the claims in the ransom note _readme.txt are true.

There are several universal methods for recovering encrypted files,[1] but the creators' decryption tool is most likely not developed or at least not provided for the victims. This is the Djvu ransomware family member, so we have a few tricks for the file recovery below. It is vital to read the entire instruction manual carefully and make sure you understand the risks and the consequences of the infection.

Once the machine is infected with the Iisa virus, it can create major issues when encoding data and running processes are not enough. This threat also adds files on your computer to control persistence while avoiding detection by masquerading as Windows update pop-ups that prompt people for security scans without revealing its true purpose – attacking you from within!

Name Iisa virus
Type Ransomware, file-locker, cryptovirus
Family Djvu/STOP ransomware
File extension .iisa gets added at the end of every original filename
Distribution Spam email attachments, software cracks, game cheats, and other files delivered online can contain virus payload
Ransom note _readme.txt
Contact manager@mailtemp.ch and helprestoremanager@airmail.cc
Ransom amount $490/$980
Elimination The threat can be terminated with the help of tools like SpyHunter 5Combo Cleaner or Malwarebytes that can find and delete the infection
Repair It is possible that many issues are created due to the virus damage on the machine, so repair the affected files and settings yourself ReimageIntego

What do you need to know about ransomware?

The Iisa virus is ransomware that infects your machine and immediately alters files, this nasty program overwrites original content with an encoded version and renames them to include the unique appendix at the file end. Like most types of malware out there today, ransomware is created to make a profit for the developers and associates.

It is always best to avoid these types of situations if possible, but sometimes you can not help it, and the malware finds you. If this is the case and your computer has been infected with ransomware, some things need immediate attention, like backing up data on an external drive before cutting all ties from other sources. The Iisa ransomware may affect system performance over time, so some steps need to be taken as soon as possible.

Cybercriminals behind the virus can be contacted using manager@mailtemp.ch or helprestoremanager@airmail.cc email address, but you receive the promised decryptor only if you pay them $490/$980. Paying for the decryption software and key can be dangerous. Even though criminals offer the discount for the ransom price it gets bigger after 72 hours without contact from victims. Experts[2] note that it is dangerous and mainly useless to pay.

iisa file virusFile-locker relies on encryption methods, so data can get locked

The possible decryption for Iisa virus

This dangerous ransomware is a version of the Djvu ransomware that releases version after version weekly. The previously known variants were easily decryptable, but the Iisa ransomware is not because of the altered encryption process and method. These newer versions use the online ID forming method that means each affected device gets the one-of-a-kind key needed for the decryption.

Previously offline id method allowed many victims to get their files restored with one key obtained from the victim. Right now, all the variants of the family are non-decryptable because of the changes made in 2019. If your computer got infected with one of the Djvu variants, you should try using Emsisoft decryptor for Djvu/STOP. It is important to mention that this tool will not work for everyone – it only works if data was locked with an offline ID due to malware failing to communicate with its remote servers.

Even if your case meets this condition, somebody from the victims has to pay criminals, retrieve an offline key, and then share it with security researchers at Emsisoft. As a result, you might not be able to restore the encrypted files immediately. Thus, if the decryptor says your data was locked with an offline ID but cannot be recovered currently, you should try later. You also need to upload a set of files – one encrypted and a healthy one to the company's servers before you proceed.

  • Download the app from the official Emsisoft website.
  • After pressing the Download button, a small pop-up at the bottom, titled decrypt_STOPDjvu.exe should show up – click it.
  • If User Account Control (UAC) message shows up, press Yes.
  • Agree to License Terms by pressing Yes.
    Iisa ransomware
  • After Disclaimer shows up, press OK.
  • The tool should automatically populate the affected folders, although you can also do it by pressing Add folder at the bottom.
    Iisa ransomware
  • Press Decrypt.
    Iisa ransomware

From here, there are three available outcomes:

  1. Decrypted!” will be shown under files that were decrypted successfully – they are now usable again.
  2. Error: Unable to decrypt file with ID:” means that the keys for this version of the virus have not yet been retrieved, so you should try later.
  3. This ID appears to be an online ID, decryption is impossible” – you are unable to decrypt files with this tool.

Steps of getting the system back to safety

Cybercriminals use Trojans or malicious emails to distribute their malware payload. Emails can be distributed with file attachments as MS files or executables. The threat can be included: inside the file itself (hidden among other code); linked with malicious links in text messages and online ads, even those looking innocent enough.

Malicious files might also arrive via Peer-to-Peer networks like torrent clients, where users infect computers by opening them without realizing what the contents include. This family is known for spreading around its payload with the help of chest for games, cracks for popular software. Malicious software often comes through third-party websites offering free downloads too.

Iisa virus can act in the background immediately after the infiltration. Even though encryption is not the first process, the threat runs on the device. This cryptocurrency extortion virus can create major issues when the machine is infiltrated, and encoded data is not just a problem this threat creates.

Ransomware like this adds various processes on your computer to control its persistence as well avoid detection[3] by masking itself with fake Windows update pop-ups. You need to remove the infection as soon as possible to avoid other issues that the Iisa ransomware virus can create. You can do that with apps like SpyHunter 5Combo Cleaner or Malwarebytes.

IISA file-locker virusAnti-malware tools can help with removal if the app is capable of detecting the infection

Once a computer is infected with malware, its system is changed to operate differently. For example, an infection can alter the Windows registry database, damage vital bootup, and other sections, delete or corrupt DLL files, etc. Once a system file is damaged by malware, antivirus software cannot do anything about it, leaving it just the way it is. Consequently, users might experience performance, stability, and usability issues, to the point where a full Windows reinstallation is required.

Therefore, we highly recommend using a one-of-a-kind, patented technology of ReimageIntego repair. Not only can it fix virus damage after the infection, but it is also capable of removing malware that has already broken into the system thanks to several engines used by the program. Besides, the application is also capable of fixing various Windows-related issues that are not caused by malware infections, for example, Blue Screen errors, freezes, registry errors, damaged DLLs, etc.

  • Download the application by clicking on the link above
  • Click on the ReimageRepair.exe
    Reimage download
  • If User Account Control (UAC) shows up, select Yes
  • Press Install and wait till the program finishes the installation process.
  • The analysis of your machine will begin immediatelyReimage scan
  • Once complete, check the results – they will be listed in the Summary
  • You can now click on each of the issues and fix them manually
  • If you see many problems that you find difficult to fix, we recommend you purchase the license and fix them automatically.Reimage results

By employing a tool like this, you would not have to worry about future computer issues, as most of them could be fixed quickly by performing a full system scan at any time. Most importantly, you could avoid the tedious process of Windows reinstallation in case things go very wrong due to one reason or another.

File recovery options

Note that removing the threat is not the same as the decryption, but it is extremely important to clear the system before you attempt any recovery. Rely on the tools mentioned and remove the Iisa file virus right away, double-check to see if the virus damage is taken care of, and then you can move to the options for file recovery.

There are some different methods for data recovery after ransomware attacks. The decryption tool would be the best, but it is not available right now. Other methods are listed below. Each of these approaches may work in some cases where others fail – following each one closely could save your data from certain losses completely if nothing else can help restore what was lost first.

Since many users do not prepare proper data backups prior to being attacked by ransomware, they might often lose access to their files permanently. Paying criminals behind the Iisa ransomware is also very risky, as they might not fulfill the promises and never send back the required decryption tool.

While this might sound terrible, not all is lost – data recovery software might be able to help you in some situations (it highly depends on the encryption algorithm used, whether ransomware managed to complete the programmed tasks, etc.). Since there are thousands of different ransomware strains, it is immediately impossible to tell whether third-party software will work for you.

Therefore, we suggest trying regardless of which ransomware attacked your computer. Before you begin, several pointers are important while dealing with this situation:

  • Since the encrypted data on your computer might permanently be damaged by security or data recovery software, you should first make backups of it – use a USB flash drive or another storage.
  • Only attempt to recover your files using this method after you perform a scan with anti-malware software.

Install data recovery software

  1. Download Data Recovery Pro.
  2. Double-click the installer to launch it.
  3. Follow on-screen instructions to install the software.
  4. As soon as you press Finish, you can use the app.
  5. Select Everything or pick individual folders where you want the files to be recovered from.Select what to recover
  6. Press Next.
  7. At the bottom, enable Deep scan and pick which Disks you want to be scanned.Select Deep scan
  8. Press Scan and wait till it is complete.
  9. You can now pick which folders/files to recover – don't forget you also have the option to search by the file name!
  10. Press Recover to retrieve your files.Recover files

The modern world is constantly changing, and because of this, there are many ways for malware to enter your computer. Some examples include email spamming/malicious attachments in emails; by misleading downloads or direct links on websites you visit- even if they seem safe.

Another way that viruses can get inside involves exploiting software vulnerabilities that would allow them access without permission from the owner. There are also many possible ways to get rid of Iisa ransomware, but you need to be sure the threat is eliminated before choosing any of the methods.

Rely on SpyHunter 5Combo Cleaner or Malwarebytes for help when dealing with an infection like this. Tools like AV-detection-based apps can also prevent virus removal in the first place if used occasionally enough – so don't hesitate to give them a try. Also, do not underestimate the malware and its functions, virus damage, and leftovers can still create issues. Trust the ReimageIntego tool for system repair.

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What to do if failed?
If you failed to fix virus damage using Reimage Intego, submit a question to our support team and provide as much details as possible.
Reimage Intego has a free limited scanner. Reimage Intego offers more through scan when you purchase its full version. When free scanner detects issues, you can fix them using free manual repairs or you can decide to purchase the full version in order to fix them automatically.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Reimage, try running SpyHunter 5.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Intego, try running Combo Cleaner.

Getting rid of Iisa virus. Follow these steps

Important steps to take before you begin malware removal

File encryption and ransomware infection are two independent processes (although the latter would not be possible without the former). However, it is important to understand that malware performs various changes within a Windows operating system, fundamentally changing the way it works.

IMPORTANT for those without backups! → 
If you attempt to use security or recovery software immediately, you might permanently damage your files, and even a working decryptor then would not be able to save them.

Before you proceed with the removal instructions below, you should copy the encrypted files onto a separate medium, such as USB flash drive or SSD, and then disconnect them from your computer. Encrypted data does not hold any malicious code, so it is safe to transfer to other devices.

The instructions below might initially seem overwhelming and complicated, but they are not difficult to understand as long as you follow each step in the appropriate order. This comprehensive free guide will help you to handle the malware removal and data recovery process correctly.

If you have any questions, comments, or are having troubles with following the instructions, please do not hesitate to contact us via the Ask Us section.

IMPORTANT! →
It is vital to eliminate malware infection from the computer fully before starting the data recovery process, otherwise ransomware might re-encrypt retrieved files from backups repeatedly.

Isolate the infected computer

Some ransomware strains aim to infect not only one computer but hijack the entire network. As soon as one of the machines is infected, malware can spread via network and encrypt files everywhere else, including Network Attached Storage (NAS) devices. If your computer is connected to a network, it is important to isolate it to prevent re-infection after ransomware removal is complete.

The easiest way to disconnect a PC from everything is simply to plug out the ethernet cable. However, in the corporate environment, this might be extremely difficult to do (also would take a long time). The method below will disconnect from all the networks, including local and the internet, isolating each of the machines involved.

  • Type in Control Panel in Windows search and press Enter
  • Go to Network and Internet Network and internet
  • Click Network and Sharing Center Network and internet 2
  • On the left, pick Change adapter settings Network and internet 3
  • Right-click on your connection (for example, Ethernet), and select Disable Network and internet 4
  • Confirm with Yes.

If you are using some type of cloud storage you are connected to, you should disconnect from it immediately. It is also advisable to disconnect all the external devices, such as USB flash sticks, external HDDs, etc. Once the malware elimination process is finished, you can connect your computers to the network and internet, as explained above, but by pressing Enable instead.

Restore Windows "hosts" file to its original state

Some ransomware might modify Windows hosts file in order to prevent users from accessing certain websites online. For example, Djvu ransomware variants add dozens of entries containing URLs of security-related websites, such as 2-spyware.com. Each of the entries means that users will not be able to access the listed web addresses and will receive an error instead.

Here's an example of “hosts” file entries that were injected by ransomware:

Hosts file

In order to restore your ability to access all websites without restrictions, you should either delete the file (Windows will automatically recreate it) or remove all the malware-created entries. If you have never touched the “hosts” file before, you should simply delete it by marking it and pressing Shift + Del on your keyboard. For that, navigate to the following location:

C:\\Windows\\System32\\drivers\\etc\\

Delete Windows "hosts" file

Create data backups to avoid file loss in the future

One of the many countermeasures for home users against ransomware is data backups. Even if your Windows get corrupted, you can reinstall everything from scratch and retrieve files from backups with minimal losses overall. Most importantly, you would not have to pay cybercriminals and risk your money as well.

Therefore, if you have already dealt with a ransomware attack, we strongly advise you to prepare backups for future use. There are two options available to you:

  • Backup on a physical external drive, such as a USB flash drive or external HDD.
  • Use cloud storage services.

The first method is not that convenient, however, as backups need to constantly be updated manually – although it is very reliable. Therefore, we highly advise choosing cloud storage instead – it is easy to set up and efficient to sustain. The problem with it is that storage space is limited unless you want to pay for the subscription.

Using Microsoft OneDrive

OneDrive is a built-in tool that comes with every modern Windows version. By default, you get 5 GB of storage that you can use for free. You can increase that storage space, but for a price. Here's how to setup backups for OneDrive:

  1. Click on the OneDrive icon within your system tray.
  2. Select Help & Settings > Settings.
    Go to OneDrive settings
  3. If you don't see your email under the Account tab, you should click Add an account and proceed with the on-screen instructions to set yourself up.
    Add OneDrive account
  4. Once done, move to the Backup tab and click Manage backup.
    Manage backup
  5. Select Desktop, Documents, and Pictures, or a combination of whichever folders you want to backup.
  6. Press Start backup.
    Pick which folders to sync

After this, all the files that are imported into the above-mentioned folders will be automatically backed for you. If you want to add other folders or files, you have to do that manually. For that, open File Explorer by pressing Win + E on your keyboard, and then click on the OneDrive icon. You should drag and drop folders you want to backup (or you can use Copy/Paste as well).

Using Google Drive

Google Drive is another great solution for free backups. The good news is that you get as much as 15GB for free by choosing this storage. There are also paid versions available, with significantly more storage to choose from.

You can access Google Drive via the web browser or use a desktop app you can download on the official website. If you want your files to be synced automatically, you will have to download the app, however.

  1. Download the Google Drive app installer and click on it.
    Install Google Drive app
  2. Wait a few seconds for it to be installed. Complete installation
  3. Now click the arrow within your system tray – you should see Google Drive icon there, click it once.
    Google Drive Sign in
  4. Click Get Started. Backup and sync
  5. Enter all the required information – your email/phone, and password. Enter email/phone
  6. Now pick what you want to sync and backup. You can click on Choose Folder to add additional folders to the list.
  7. Once done, pick Next. Choose what to sync
  8. Now you can select to sync items to be visible on your computer.
  9. Finally, press Start and wait till the sync is complete. Your files are now being backed up.

Report the incident to your local authorities

Ransomware is a huge business that is highly illegal, and authorities are very involved in catching malware operators. To have increased chances of identifying the culprits, the agencies need information. Therefore, by reporting the crime, you could help with stopping the cybercriminal activities and catching the threat actors. Make sure you include all the possible details, including how did you notice the attack, when it happened, etc. Additionally, providing documents such as ransom notes, examples of encrypted files, or malware executables would also be beneficial.

Law enforcement agencies typically deal with online fraud and cybercrime, although it depends on where you live. Here is the list of local authority groups that handle incidents like ransomware attacks, sorted by country:

Internet Crime Complaint Center IC3

If your country is not listed above, you should contact the local police department or communications center.

Manual removal using Safe Mode

Important! →
Manual removal guide might be too complicated for regular computer users. It requires advanced IT knowledge to be performed correctly (if vital system files are removed or damaged, it might result in full Windows compromise), and it also might take hours to complete. Therefore, we highly advise using the automatic method provided above instead.

Step 1. Access Safe Mode with Networking

Manual malware removal should be best performed in the Safe Mode environment. 

Windows 7 / Vista / XP
  1. Click Start > Shutdown > Restart > OK.
  2. When your computer becomes active, start pressing F8 button (if that does not work, try F2, F12, Del, etc. – it all depends on your motherboard model) multiple times until you see the Advanced Boot Options window.
  3. Select Safe Mode with Networking from the list. Windows 7/XP
Windows 10 / Windows 8
  1. Right-click on Start button and select Settings.
    Settings
  2. Scroll down to pick Update & Security.
    Update and security
  3. On the left side of the window, pick Recovery.
  4. Now scroll down to find Advanced Startup section.
  5. Click Restart now.
    Reboot
  6. Select Troubleshoot. Choose an option
  7. Go to Advanced options. Advanced options
  8. Select Startup Settings. Startup settings
  9. Press Restart.
  10. Now press 5 or click 5) Enable Safe Mode with Networking. Enable safe mode

Step 2. Shut down suspicious processes

Windows Task Manager is a useful tool that shows all the processes running in the background. If malware is running a process, you need to shut it down:

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Click on More details.
    Open task manager
  3. Scroll down to Background processes section, and look for anything suspicious.
  4. Right-click and select Open file location.
    Open file location
  5. Go back to the process, right-click and pick End Task.
    End task
  6. Delete the contents of the malicious folder.

Step 3. Check program Startup

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Go to Startup tab.
  3. Right-click on the suspicious program and pick Disable.
    Startup

Step 4. Delete virus files

Malware-related files can be found in various places within your computer. Here are instructions that could help you find them:

  1. Type in Disk Cleanup in Windows search and press Enter.
    Disk cleanup
  2. Select the drive you want to clean (C: is your main drive by default and is likely to be the one that has malicious files in).
  3. Scroll through the Files to delete list and select the following:

    Temporary Internet Files
    Downloads
    Recycle Bin
    Temporary files

  4. Pick Clean up system files.
    Delete temp files
  5. You can also look for other malicious files hidden in the following folders (type these entries in Windows Search and press Enter):

    %AppData%
    %LocalAppData%
    %ProgramData%
    %WinDir%

After you are finished, reboot the PC in normal mode.

Finally, you should always think about the protection of crypto-ransomwares. In order to protect your computer from Iisa and other ransomwares, use a reputable anti-spyware, such as ReimageIntego, SpyHunter 5Combo Cleaner or Malwarebytes

How to prevent from getting ransomware

Stream videos without limitations, no matter where you are

There are multiple parties that could find out almost anything about you by checking your online activity. While this is highly unlikely, advertisers and tech companies are constantly tracking you online. The first step to privacy should be a secure browser that focuses on tracker reduction to a minimum.

Even if you employ a secure browser, you will not be able to access websites that are restricted due to local government laws or other reasons. In other words, you may not be able to stream Disney+ or US-based Netflix in some countries. To bypass these restrictions, you can employ a powerful Private Internet Access VPN, which provides dedicated servers for torrenting and streaming, not slowing you down in the process.

Data backups are important – recover your lost files

Ransomware is one of the biggest threats to personal data. Once it is executed on a machine, it launches a sophisticated encryption algorithm that locks all your files, although it does not destroy them. The most common misconception is that anti-malware software can return files to their previous states. This is not true, however, and data remains locked after the malicious payload is deleted.

While regular data backups are the only secure method to recover your files after a ransomware attack, tools such as Data Recovery Pro can also be effective and restore at least some of your lost data.

About the author
Ugnius Kiguolis
Ugnius Kiguolis - The mastermind

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References
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