What is JSSLOADER?
JSSLOADER is a Remote Access Trojan (RAT) capable of exfiltrating data, executing commands, downloading other malware, auto-updating itself and preventing itself from being debugged (analyzed). JSSLOADER is mostly used by the group of cyber criminals called FIN7.
At first, JSSLOADER collects (exfiltrates) data such as AD (Active Directory) information, domain name, desktop files, host name, logical drives, network information, running processes, system information, and usernames, and sends it to a specific URL address.
Attackers the use the information to send CMD commands from a Command and control (C2) server, which could include commands to write and run executable files, rewrite JSSLOADER with its updated version, uninstall JSSLOADER (and remove the persistency, terminate its process), execute a PowerShell command, and write and execute a DLL file.
Research shows that one of the main commands that attackers execute via JSSLOADER is "Cmd_RAT", which executes a Takeout script - this loads and executes Carbanak (data-stealing banking malware).
Typically, malware of this type is used to steal financial information (such as credit card details and bank account numbers), login credentials, and other private, sensitive information.
|Name||JSSLOADER Remote Access Trojan|
|Threat Type||Remote Access Trojan|
|Detection Names||Avast (Other:Malware-gen [Trj]), BitDefender (VBS.Heur.Maltzur.1.013F4BB5.Gen), Emsisoft (VBS.Heur.Maltzur.1.013F4BB5.Gen (B)), Kaspersky (HEUR:Trojan-Downloader.Script.Generic), Microsoft (TrojanDownloader:VBS/Qakbot.AR!MTB), Full List (VirusTotal)|
|Malicious Process Name(s)||MimiHealth (its name may vary)|
|Symptoms||Remote Administration Trojans are designed to stealthily infiltrate the victim's computer and remain silent, and thus no particular symptoms are clearly visible on an infected machine.|
|Distribution methods||Infected email attachments, malicious online advertisements, social engineering, software 'cracks'.|
|Damage||Stolen passwords and banking information, identity theft, the victim's computer added to a botnet.|
|Malware Removal (Windows)||
To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Combo Cleaner.
In summary, cyber criminals behind JSSLOADER can use it to collect specific data (including files placed on the desktop) and execute commands to install the aforementioned banking malware and other malicious software.
How did JSSLOADER infiltrate my computer?
JSSLOADER is distributed via malspam emails. Typically, these emails contain a malicious attachment or download link for a malicious file. To trick recipients into opening the malicious file, cyber criminals disguise these emails as important, official messages from legitimate companies and organizations.
Their main goal is to trick recipients into opening/executing the rogue file, which then installs malicious software.
Note that malicious documents that are opened with Microsoft Office 2010 or newer versions install malicious software only if users enable macros commands (enable editing/content). These versions include "Protected View" mode, which does not allow opened malicious documents to install malware automatically. Older versions do not include this feature and install malicious software without asking permission.
How to avoid installation of malware
You are advised to research all software before download/installation. Use only official and verified download channels. Unofficial and free file-hosting websites, Peer-to-Peer sharing networks (BitTorrent, Gnutella, eMule), and other third party downloaders commonly offer harmful and bundled content, and are therefore untrusted and should be avoided.
When downloading/installing, read the terms, study all possible options, use the "Custom/Advanced" settings and opt-out of additional apps, tools, features, and so on.
Intrusive advertisements typically seem legitimate, however, they can redirect to dubious and malicious sites (e.g. gambling, pornography, adult-dating, and many others). If you encounter ads or redirects of this kind, inspect the system and remove all dubious applications and browser extensions/plug-ins immediately.
Installed programs must be activated and updated with tools or implemented functions that are provided by the official developers. No other third party, unofficial tools should be used.
Note that it is illegal to activate licensed software with ‘cracking’ tools. Files and programs should be downloaded from official websites and via direct download links. Avoid third party installers and the tools/sources mentioned above.
Do not open website links or files in irrelevant emails that are received from unknown, suspicious addresses. These bogus emails are often disguised as official and important. Regularly, scan your computer with reputable, up-to-date antivirus or anti-spyware software.
If you believe that your computer is already infected, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate infiltrated malware.
JSSLOADER running in Task Manager as "MimiHealth" (its name may vary):
Example of a malicious Microsoft Word document used to inject JSSLOADER RAT into the system:
Instant automatic malware removal:
Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Combo Cleaner is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:
- What is JSSLOADER?
- STEP 1. Manual removal of JSSLOADER malware.
- STEP 2. Check if your computer is clean.
How to remove malware manually?
Manual malware removal is a complicated task - usually it is best to allow antivirus or anti-malware programs to do this automatically. To remove this malware we recommend using Combo Cleaner Antivirus for Windows.
If you wish to remove malware manually, the first step is to identify the name of the malware that you are trying to remove. Here is an example of a suspicious program running on a user's computer:
If you checked the list of programs running on your computer, for example, using task manager, and identified a program that looks suspicious, you should continue with these steps:
Download a program called Autoruns. This program shows auto-start applications, Registry, and file system locations:
Restart your computer into Safe Mode:
Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.
Video showing how to start Windows 7 in "Safe Mode with Networking":
Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button.
Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.
Video showing how to start Windows 8 in "Safe Mode with Networking":
Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button.
In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.
Video showing how to start Windows 10 in "Safe Mode with Networking":
Extract the downloaded archive and run the Autoruns.exe file.
In the Autoruns application, click "Options" at the top and uncheck "Hide Empty Locations" and "Hide Windows Entries" options. After this procedure, click the "Refresh" icon.
Check the list provided by the Autoruns application and locate the malware file that you want to eliminate.
You should write down its full path and name. Note that some malware hides process names under legitimate Windows process names. At this stage, it is very important to avoid removing system files. After you locate the suspicious program you wish to remove, right click your mouse over its name and choose "Delete".
After removing the malware through the Autoruns application (this ensures that the malware will not run automatically on the next system startup), you should search for the malware name on your computer. Be sure to enable hidden files and folders before proceeding. If you find the filename of the malware, be sure to remove it.
Reboot your computer in normal mode. Following these steps should remove any malware from your computer. Note that manual threat removal requires advanced computer skills. If you do not have these skills, leave malware removal to antivirus and anti-malware programs.
These steps might not work with advanced malware infections. As always it is best to prevent infection than try to remove malware later. To keep your computer safe, install the latest operating system updates and use antivirus software.
To be sure your computer is free of malware infections, we recommend scanning it with Combo Cleaner Antivirus for Windows.