Microsoft Security Essentials and Microsoft Windows Defender or may find Trojan:MSIL/QuasarRat!cert on the computer that is infected with a dangerous virus. This specific type of virus is able to allow an attacker to remotely access the computer to carry out various malicious actions. Trojan:MSIL/QuasarRat!cert is known to be associated with different Trojan Downloader they use to spread Internet infection.

Threat Behavior

Routine infection with Trojan:MSIL/QuasarRat!cert was observed from a Trojan Horse downloader. As a first step, the Trojan will infect the computer, then communicate to a remote host to fetch a copy of Trojan:MSIL/QuasarRat!cert.

Once Trojan:MSIL/QuasarRat!cert has infiltrated the computer, it implant copies of virus in various folders, including the System location. To run at Windows startup, Trojan:MSIL/QuasarRat!cert injects a registry which runs the code of this virus during boot-up sequence. Consequently, the threat remains a memory resident for the period in which it exists on the computer.


Trojan:MSIL/QuasarRat!cert’s task is to open a back door port on the infected computer so that the remote attacker who created the virus can access it without permission. After opening the port, this attacker can do various malicious actions, including:.

  • Contact a remote server for other malware downloads.
  • Log on to the order and control server to update the current infection.
  • Captures keyboard entries on the infected device.
  • Upload the gathered data on a remote server.
  • Engage in Denial of Service (DoS) attacks.
  • Cease all running antivirus programs.
  • Execution or termination of some valid processes on the computer.

List of Variants

List of Trojan:MSIL/QuasarRat!cert Variants
Version NameAlert LevelDate Added
Backdoor:Win32/QuasarRAT.ASevereJan 08, 2019
Backdoor:Win32/QuasarRAT.A!bitSevereFeb 11, 2019
Backdoor:MSIL/QuasarRAT.YA!MTBSevereApr 29, 2019
Backdoor:Win32/QuasarRAT!MSRSevereMar 11, 2020
Backdoor:MSIL/QuasarRat.GG!MTBSevereApr 07, 2020
Backdoor:MSIL/QuasarRAT!MTBSevereMay 07, 2020
Backdoor:MSIL/QuasarRat.GG!rfnSevereMay 16, 2020
Backdoor:Win32/QuasarRAT!mlSevereAug 10, 2020
For complete details including full list of variants, please refer to this Microsoft Security Intelligence page

How to remove Trojan:MSIL/QuasarRat!cert?

To totally remove Trojan:MSIL/QuasarRat!cert from the computer and get rid of relevant virus and trojan, please execute the procedures as stated on this page. Make sure that you have completely scan the system with suggested malware removal tools and virus scanners.

Remove Trojan:MSIL/QuasarRat!cert Instantly

To instantly remove Trojan:MSIL/QuasarRat!cert, we suggest that you scan the infected computer with this powerful anti-malware tool. It can detect and get rid of Trojans, viruses, malware, and adware from the infected computer. To fully protect the computer against Trojan:MSIL/QuasarRat!cert or similar attack, you can activate Malwarebytes to have real-time scanning and complete defense against all forms of threats.

1. Download Malwarebytes Anti-Malware from the link below. Save the file on your hard drive.

2. Once the download completes, double-click on the file MBSetup.exe to run the program.

3. Select desired installation package whether for Personal Computer or Work Computer.

4. On next window, click Install button to proceed.

MBAM Default Install

5. Just proceed with the succeeding prompts until it start to execute the installation procedure.

6. Installation process will take less than a minute. It should run automatically after completing the setup.

7. When Malwarebytes Anti-Malware interface appears, please select Scan on the menu. The program will check for any available update before proceeding. Do not skip this step. Virus scan may take a while, please wait for the process to finish.


8. When scanning is done, Malwarebytes Anti-Malware will display the list of identified threats. Remove all and restart the computer to finalized the scan process.

After executing the above instructions, Trojan:MSIL/QuasarRat!cert should have been eliminated totally from the computer. If there are still signs of infection or computer is displaying unusual behaviors, please continue with the remaining procedures.

Stage 1 : 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 2 :Double Check with Microsoft Security Apps

Microsoft Windows has built-in security application that you can use to double-check if computer is still infected with Trojan:MSIL/QuasarRat!cert. For Windows 8 and 10 users, please run Windows Defender. Users of Windows Vista and older versions can utilize Microsoft Security Essentials to remove Trojan:MSIL/QuasarRat!cert virus.

Windows 8 / 10 Instructions:

Windows Defender is a free tool that was built help you remove Trojan:MSIL/QuasarRat!cert, viruses, and other malicious items from Windows 8 or Windows 10 system. Follow these procedures to scan your computer with Windows Defender:

1. Tap or click the Search charm, search for defender, and then open Windows Defender.

If Windows Defender is not yet installed on the computer, please proceed to download page using the link below. It also contains detailed instruction to install and use the program effectively. Proper usage is required to totally remove Trojan:MSIL/QuasarRat!cert


2. On the Home tab, click Full under Scan Options. Click Scan now to start scanning for presence of Trojan:MSIL/QuasarRat!cert. The process may take a while to complete.


3. After the scan, delete/quarantine identified threats wether it is relevant to Trojan:MSIL/QuasarRat!cert or not. You may now restart Windows to complete the virus removal process.

Windows XP, Windows Vista, and Windows 7 Instructions:

1. Open Microsoft Security Essentials by going to Windows Start > All Programs. If the tool is not yet installed on the computer, please download Microsoft Security Essentials from the link below. Save the file on your hard drive.

Complete installation guide and usage are also provided on the same link. It is essential in removing Trojan:MSIL/QuasarRat!cert effectively. If Microsoft Security Essentials is already installed on the PC, please proceed with the steps below.

2. On Microsoft Security Essentials Home screen, please choose Full under Scan Options.

MSE Full Scan

3. Click on Scan Now button to start detecting Trojan:MSIL/QuasarRat!cert items, viruses, and malware on the PC. Scan may take a while, please be patient and wait for the process to end.

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