Backdoor:MSIL/Quasar!atmn Backdoor Virus (Quasar Removal)

Written by Wilbur Woodham

The Backdoor:MSIL/Quasar!atmn detection means that your computer has a problem. Allowing it to run may end up with really bad consequences. Quasar delivers the cybercriminals access to your computer, or perhaps adds it to the botnet.

Backdoors like Quasar are versatile viruses that can act as autonomous malware, as well as be used in staged attacks. Their key target is creating a remote control point to the system, that operates without the victim’s knowledge. To prevent any interruptions, backdoor aims at staying as low as possible.

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When we talk about the intrusion of unfamiliar programs into your computer’s work, the proverb “Forewarned is forearmed” describes the situation as accurately as possible. Gridinsoft Anti-Malware is exactly the tool that is always useful to have in your armory: fast, efficient, up-to-date. It is appropriate to use it as an emergency help at the slightest suspicion of infection.
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Backdoor:MSIL/Quasar!atmn Detection Overview

The Backdoor:MSIL/Quasar!atmn detection you can see in the lower right corner is shown to you by Microsoft Defender. That anti-malware application is pretty good at scanning, however, prone to be mainly unstable. It is unprotected to malware invasions, it has a glitchy user interface and problematic malware removal capabilities. Hence, the pop-up which says about the Quasar is just an alert that Defender has detected it. To remove it, you will likely need to make use of another anti-malware program.

Backdoor:MSIL/Quasar!atmn found

Microsoft Defender: “Backdoor:MSIL/Quasar!atmn”

The exact Backdoor:MSIL/Quasar!atmn malware is a very nasty thing. This malware is designed to be a stealthy intruder, which functions as a remote-access tool. When you provide somebody remote access willingly, it is alright, but Quasar will not ask you if you want to provide it. After connecting to your system, crooks are able to do whatever they want – getting your files, checking out your messages, picking up personal data, et cetera. Backdoors commonly bring an additional stealer – the virus that is designed to gather all available data about you. Nonetheless, much more widespread use of the backdoors is setting up the botnet. After that, the network of corrupted PCs may be put to use to conduct DDoS attacks or to inflate the vote results on different websites.

Backdoor Summary:

NameQuasar Backdoor
DamageGain access to the operating system to perform various malicious actions.
SimilarCur Malware, Trojan Msil Mamut, Hupigon, Luadream Malware, Pysilon Rat Malware, Sponsor Malware, Bladabindi, Loda Rat Malware
Fix ToolSee If Your System Has Been Affected by Quasar backdoor

Shortly about backdoors

Backdoors are viruses that can acquire both separated and incorporated shapes. Once you may discover that a legit program from a famous developer has a capability that allows someone to connect to your system. Will it be someone from the developers or a 3rd party – no one knows. But the scandal when this aspect is spotted in a legitimate program is almost impossible to miss. There is also gossip that there is a hardware-based backdoor in Intel CPUs1.

Is Backdoor:MSIL/Quasar!atmn dangerous?

As I have actually stated , non-harmful malware does not exist. And Backdoor:MSIL/Quasar!atmn is not an exception. This backdoor does not deal a lot of harm exactly after it launches. Nevertheless, it will be a pretty bad surprise when a random discussion forum or site in the Internet will not let you in, since your IP-address is disallowed after the DDoS attack. But even if it is not important for you – is it positive at all to understand that someone can simply access your PC, read your conversations, open your documents, and spectate what you do?

The spyware that is frequently present as a supplement to the Backdoor:MSIL/Quasar!atmn malware will be just an additional reason to remove it as fast as you can. Nowadays, when users’ data is valued remarkably high, it is too goofy to grant the crooks such a chance. Even worse if the spyware will in some way manage to grab your financial info. Seeing zeros on your savings account is the worst problem, in my opinion.

Remove Quasar with Gridinsoft Anti-Malware

We have also been using this software on our systems ever since, and it has always been successful in detecting viruses. It has blocked the most common Backdoors as shown from our tests with the software, and we assure you that it can remove Quasar as well as other malware hiding on your computer.

Gridinsoft Anti-Malware - Main Screen

To use Gridinsoft for remove malicious threats, follow the steps below:

1. Begin by downloading Gridinsoft Anti-Malware, accessible via the blue button below or directly from the official website

2.Once the Gridinsoft setup file (setup-gridinsoft-fix.exe) is downloaded, execute it by clicking on the file.


3.Follow the installation setup wizard's instructions diligently.

Gridinsoft Setup Wizard

4. Access the "Scan Tab" on the application's start screen and launch a comprehensive "Full Scan" to examine your entire computer. This inclusive scan encompasses the memory, startup items, the registry, services, drivers, and all files, ensuring that it detects malware hidden in all possible locations.

Scan for Quasar Backdoors

Be patient, as the scan duration depends on the number of files and your computer's hardware capabilities. Use this time to relax or attend to other tasks.

5. Upon completion, Anti-Malware will present a detailed report containing all the detected malicious items and threats on your PC.

The Quasar was Found

6. Select all the identified items from the report and confidently click the "Clean Now" button. This action will safely remove the malicious files from your computer, transferring them to the secure quarantine zone of the anti-malware program to prevent any further harmful actions.

The Quasar has been removed

8. If prompted, restart your computer to finalize the full system scan procedure. This step is crucial to ensure thorough removal of any remaining threats. After the restart, Gridinsoft Anti-Malware will open and display a message confirming the completion of the scan.

Remember Gridinsoft offers a 6-day free trial. This means you can take advantage of the trial period at no cost to experience the full benefits of the software and prevent any future malware infections on your system. Embrace this opportunity to fortify your computer's security without any financial commitment.

Trojan Killer for “Quasar” removal on locked PC

In situations where it becomes impossible to download antivirus applications directly onto the infected computer due to malware blocking access to websites, an alternative solution is to utilize the Trojan Killer application.

Trojan Killer - Main View

There is a really little number of security tools that are able to be set up on the USB drives, and antiviruses that can do so in most cases require to obtain quite an expensive license. For this instance, I can recommend you to use another solution of GridinSoft - Trojan Killer Portable. It has a 14-days cost-free trial mode that offers the entire features of the paid version. This term will definitely be 100% enough to wipe malware out.

Trojan Killer is a valuable tool in your cybersecurity arsenal, helping you to effectively remove malware from infected computers. Now, we will walk you through the process of using Trojan Killer from a USB flash drive to scan and remove malware on an infected PC. Remember, always obtain permission to scan and remove malware from a computer that you do not own.

Step 1: Download & Install Trojan Killer on a Clean Computer:

1. Go to the official GridinSoft website ( and download Trojan Killer to a computer that is not infected.

Download Trojan Killer

2. Insert a USB flash drive into this computer.

3. Install Trojan Killer to the "removable drive" following the on-screen instructions.

Install Trojan Killer to Removable Drive

4. Once the installation is complete, launch Trojan Killer.

Step 2: Update Signature Databases:

5. After launching Trojan Killer, ensure that your computer is connected to the Internet.

6. Click "Update" icon to download the latest signature databases, which will ensure the tool can detect the most recent threats.

Click Update Button

Step 3: Scan the Infected PC:

7. Safely eject the USB flash drive from the clean computer.

8. Boot the infected computer to the Safe Mode.

9. Insert the USB flash drive.

10. Run tk.exe

11. Once the program is open, click on "Full Scan" to begin the malware scanning process.

Searching Quasar Virus

Step 4: Remove Found Threats:

12. After the scan is complete, Trojan Killer will display a list of detected threats.

Searching Quasar Finished

13. Click on "Cure PC!" to remove the identified malware from the infected PC.

14. Follow any additional on-screen prompts to complete the removal process.

Restart needed

Step 5: Restart Your Computer:

15. Once the threats are removed, click on "Restart PC" to reboot your computer.

16. Remove the USB flash drive from the infected computer.

Congratulations on effectively removing Quasar and the concealed threats from your computer! You can now have peace of mind, knowing that they won't resurface again. Thanks to Gridinsoft's capabilities and commitment to cybersecurity, your system is now protected.

What is Backdoor:MSIL/Quasar!atmn Virus?

Name: Backdoor:MSIL/Quasar!atmn

Description: If you have seen a message showing the “Backdoor:MSIL/Quasar!atmn found”, it seems that your system is in trouble. The Quasar virus was detected, but to remove it, you need to use a security tool. Windows Defender, which has shown you this message, has detected the malware. However, Defender is not a reliable thing - it is prone to malfunction when it comes to malware removal. Getting the Backdoor:MSIL/Quasar!atmn malware on your PC is an unpleasant thing, and removing it as soon as possible must be your primary task.

Operating System: Windows

Application Category: Backdoor

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  1. Gossip about the backdoor in Intel processors on Reddit.

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About the author

Wilbur Woodham

I was a technical writer from early in my career, and consider IT Security one of my foundational skills. I’m sharing my experience here, and I hope you find it useful.

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