Remove Iiss Ransomware (.iiss File Decryption)

Iiss ransomware is a file-locker virus that emerges from STOP/DJVU family. This recent edition is just a remake from previous ones and seems to be that attacker has re-used the same code, spread techniques, and payload. Iiss ransomware attacks the computer and aims to lock majority of computer user’s files. Then it will ask for ransom payment as trade off for the Iiss decryption tool that is necessary to restore all the encrypted files.

Iiss ransomware infection

This crypto-virus spreads in different methods like web injectors, pirated software, spam emails, malicious software bundles, fake software updates, and deceiving online ads. Hence, it is through spam email campaign that attackers found high infection success rate.

The technique is, Iiss ransomware is incorporated to email as file attachment disguising as valid document. It arrives on inbox as usual business email with topics relating to inquiry, tax, payment method, delivery, shipping, invoice, or anything that are associated to work and office. The message commonly points to attachment as having the significant content and because of that, it can trick the recipient to open the embedded file that will eventually run Iiss ransomware attack.

Same thing with other deployment scheme, computer users will be tricked to execute the supposed software or link from malicious websites in order to get the Iiss ransomware running.

Image of Iiss encrypted files

Encryption and file recovery

As soon as Iiss ransomware is executed, it sends signals to command-and-control server and wait for additional modules, keys, and commands. Once it obtained the necessary objects, Iiss ransomware starts to encrypt the files with advanced technique. Along the way, this virus appends the data with .iiss file extension. As a result, the common portrait.jpg will become portrait.jpg.iiss once it is fully encrypted. Then, Iiss ransomware will generate a ransom note stating the current situation. The document also contains instructions to recover all .iiss encrypted files. As usual, attackers are asking for ransom payment from victims. Here is an excerpt from the ransom note.

Technical Details
Threat NameIiss Ransomware, Stop, DJVU
Threat TypeCrypto-virus, File Locker, Encryption Virus
File Extension.iiss
Ransomware Note File_readme.txt
Discovered by@demoslay335
Virus AliasAVG : FileRepMalware
BitDefender : Gen:NN.ZexaF.34590.SqW@aSNMp5UG
ESET-NOD32 : A Variant Of Win32/Kryptik.HHAE
Kaspersky : UDS:DangerousObject.Multi.Generic
McAfee : BehavesLike.Win32.Generic.bc
Microsoft : Ransom:Win32/STOP.BS!MTB
Rising : Trojan.Generic@ML.91
Sophos : ML/PE-A
Symantec : ML.Attribute.HighConfidence
ZoneAlarm : UDS:DangerousObject.Multi.Generic

For complete details including full detection list, hash file, file names, and technical behavior (registry actions, shell commands, and processes) of Iiss ransomware, please refer to this VirusTotal page.

Backup your files

One important step before proceeding with the procedures below is to backup your files. Ransomware are not the same. Each has its unique sets of payloads aside from encrypting the files with complex method. Others tend to delete the infected files after certain period, while others keep them concealed on hidden places. In addition, ransomware decryption tools are not guaranteed to be perfect, there are instances that files suffer from damages during the decryption process.

So, create a backup copy of your entire Iiss encrypted files right now.

Iiss Ransomware Removal Guide

First thing to do is remove the Iiss virus before attempting the decryption. Remember that as long as the ransomware is active, it will repeatedly encrypt the files on the compromised computer.

Infection of Iiss ransom virus is dangerous to the system because it can inject files that runs each time Windows starts. To prevent the malicious files from loading, Windows operating system must run with minimal process and it can be done through SafeMode With Networking.

Stage 1 : Temporarily Disable System Restore on Windows OS

Because Iiss and relevant virus is capable of reinstating itself by exploiting the System Restore of Windows, we suggests that you temporary disable System Restore while executing the steps. This option is also helpful to effectively run a full scan on the computer.

Do not forget to enable back System Restore after completing the removal of Iiss ransomware. This feature is vital in reinstating the operating system to previous normal working condition in case of problems or conflicts occurs.

Stage 2 : Start Windows in Safe Mode With Networking

Windows 10 Guide

1. Click on Windows logo and select Power icon when options pop-ups.
2. Select Restart from the options while pressing Shift key on the keyboard.
3. Choose an Option window will appear, select the Troubleshoot button.
4. On next window, please choose Advanced Option.
5. On Advanced Option window, click on Startup Settings and then, click Restart button to reboot the computer.
6. When Windows boot on Startup Settings, press function key F5 or number 5 on keyboard.

A simpler alternative for Windows 10 users is to scan the computer with Microsoft Defender Offline. This will run a virus scan in the recovery environment.

Windows 8 Guide

1. Click Windows Start icon at the lower left section of the screen.
2. Open Search window and type Advanced in the field. It will open General PC Settings.
3. Click on Advanced Startup and then, click on Restart Now button.
4. Once the computer starts in Advanced Startup option menu, select Troubleshoot.
5. Next, click on Advanced Options to reveal the next section.
6. Click Startup settings and then, click Restart button to boot the PC in Startup Settings.
7. Use function key F5 or number key 5 to Enable Safe Mode with Networking.

Stage 3 : Scan the Computer with Anti-Malware Tool

Ransomware files are placed deeply into the system and on various locations, thus, thorough scanning is vital to totally remove Iiss virus. Aside from our suggested tool, you may also run your own security program.

To remove Iiss automatically, scanning the computer with this efficient anti-malware tool is suggested. This scanner does not just uncover known threats like viruses or malware, it is also effective in discovering hazardous ransomware like Iiss.

1. Download free anti-malware scanner called MalwareBytes Anti-Malware.

2. After downloading, install the program. It may run automatically or you have to double-click on the downloaded file MBSetup.exe.

3. Carry out the installation with default setup process.

4. After the installation process, click the Get Started button to launch the program.

5. Continue with the prompts until the main program opens.

6. On the main console, click on Scan to run most complete detection method to find hidden objects associated to Iiss ransomware.

7. Scanning may take a while. Please wait until the anti-malware tool is done with the checking.

MBAM Scan

8. Once the scan has completed, the tool will display the list of detected threats. Remove all identified malicious items and restart the computer if necessary.

Stage 4 : Double-check with Microsoft's Malicious Software Removal Tool

1. Download the free scanner called Malicious Software Removal Tool.

Download MSRT

2. The tool automatically checks the operating system and suggest appropriate download version. Click on Download button to begin. Save the file to a convenient location, preferably on Desktop.

3. After downloading the file, Windows will prompt that download has completed. Click Run to start scanning for Iiss ransomware. Another option is to browse the location folder and double click on the file to run.

MSRT Icon

4. The tool will display Welcome screen, click Next. Please note the message "This tool is not a replacement for an antivirus product." You must understand that this program is made specifically to find and remove malware, viruses, Trojans, and other harmful elements on the computer. It was not designed to protect the computer.

MSRT Welcome

5. Next, you will see Scan Type. Please choose Full Scan to ensure that all Iiss ransom virus entities and other harmful files left on the computer will be found and removed. For advanced computer user, you can opt for Customized Scan, if there are other drives or folders you wanted to include in this scan.

MSRT Scan

6. Full scan may take a while, please wait for Malicious Software Removal Tool to complete the tasks. However, you may cancel the scan anytime by clicking on the Cancel button.

MSRT Scan

7. After scanning, the tool will reveal all identified threats. There may be other threats that our first scan fails to detect. Please remove/delete all detected items.

8. When removal procedure is complete, you may now close Malicious Software Removal Tool. We hope that Iiss ransomware have been completely deleted from the computer. Please restart Windows to proceed with the normal operation.

Recover Files from Iiss Ransomware Infection

On this section, we will provide ways to decrypt files infected with Iiss ransomware. Aside from dedicated decryption software and common tools, other options for file recovery are provided. As much as we can, we will update this area whenever there is new and more suitable decryption tool was made available.

Decrypting Iiss infected files with Emsisoft Tools

This service from Emsisoft is helpful in unlocking encrypted files without paying the ransom. It gives three ways to detect the ransomware and provide suitable recovery method:

Upload ransom note – This is usually the .txt or .hta files that was generated by Iiss ransomware.

Upload the encrypted file – The actual encrypted file. Choose the one that is less than 8MB in size.

Contact information – Enter the email address or any links provided as it appears in the ransom note of Iiss virus.

Emsisoft Tools

After submitting any of the appropriate data, Emsisoft will attempt to identify the ransomware and provide keys if there are available.

Option 1: Windows Previous Version Tool

Windows Vista and Windows 7 have a feature called Previous Versions. However, this tool is only usable if restore point was made prior to ransomware infection. To use this tool as "recovery option" for files encypted by Iiss virus, please follow these steps:

1. Open My Computer or Windows Explorer.

2. Right-click on the affected files or folders. From the drop-down list, please click on Restore previous versions.

3. New window will open display all backup copy of files and folders you wanted to recover. Choose the appropriate file and click on Open, Copy, or Restore. Restoring selected files overwrites the current locked files on the computer. The tool is not actually recovering files encrypted by Iiss. Instead, it restores files from backup copy.

Option 2: Use ShadowExplorer to restore files encrypted by Iiss Ransomware

Just like Previous Version tool, ShadowExplorer is taking advantage of shadow copy created by Windows. This tool allows you to retrieve older version of files before it was encrypted by Iiss ransomware.

1. Download ShadowExplorer from the official web site.

2. Install the program with the default settings.

3. The program should run automatically after installation. If not, double-click on ShadowExplorer icon.

4. You can see the drop-down list on top of the console. Please select proper drive and the most recent point-in-time shadow copies of files you wish to restore prior to Iiss ransomware infection.

shadow3

5. Right-click on the Drive, Folder, or File you wish to restore and click Export...

6. Lastly, ShadowExplorer will prompt for location where you want to save the copy of recovered files.

How to protect the computer from Iiss ransomware?

After the removal of the ransomware, it is important to prevent similar incident from happening again. In order to protect the computer effectively, computer user must know how Iiss ransomware was able to infect the computer. To minimize the possible infection, staying away from the common sources of this virus is crucial.

How Iiss ransomware can infect your computer?

The method of infecting the computers was found to be similar as other common viruses. Though, ransomware like Iiss is seen to have efficient deployment via spam email messages, web injectors, malicious software installers, misleading online advertisements, and through another virus infection.

Once the virus is executed, it immediately infects the system. Then, Iiss ransomware communicates to remote server so that unique key can be generated for the specific computer. After acquiring the key, it starts to decrypt target files using a complex method that is almost unbreakable. On the last stage of the attack, Iiss ransomware demands for ransom money as payment for the decryption tool. To further understand the attack scheme, we have included an infographic below.

Infographic image of ransomware attack stages
You can print, download, or share the infographic by clicking the image.

Securing the computer against ransomware attack

Do a Regular File Back-up - Always backup your data on a separate storage devices such as external hard drives, optical discs, or online backup services.

Keep Your Software Updated - Make sure that you have the latest software updates especially on the operating system. Recent updates often contain vital security patches to help protect the computer against all forms of threats.

Install a Security Program - Protect the computer with effective anti-virus application using efficient real-time scanning. Regularly run a complete scan to check the computer for presence of malware.

Protect your files with Controlled Folder Access (Windows 10)

For Windows 10 users, aside from protecting the computer using anti-virus or anti-malware programs, one way to protect against ransomware attack is by using Controlled Folder Access. This feature of Windows Defender Security Center may not prevent the Iiss ransomware infection, but it can protect the folder and files in general. Follow the steps to enable Controlled Folder Access in Windows 10.

1. Go to Windows 10 Taskbar and search for Windows Defender Security Center.

2. Open Windows Defender Security Center and click on Virus & Threat Protection icon.

Virus and Threat Protection

3. On next window, please click on Ransomware Protection.

4. Under Controlled Folder Access section, switch the slider to On. That will enable the feature and protect the folder against Iiss or any type of ransomware.

Controlled Folder Access

5. Click on Protected Folderslink to include additional folders. Make sure that folders where important files are located should be included in the list.

Add Protected Folder

Troubleshooting Guide

Certain programs maybe blocked by Controlled Folder Access feature. To fix the issue, simply have the specific program to be white listed.

1. Under Protected Folders, click Allow an app through controlled folder access.

2. Next, click the Add an allowed app and include the target executable file.

This Controlled Folder Access feature is one way to protect files against Iiss. Other important things to do in keeping files safe against ransomware is through early prevention like keeping programs updated, install an efficient security program, an do regular file backup on a separate media drive.

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