TrojanSpy:MSIL/AgentTesla is a detection by Microsoft Defender Antivirus for a computer threat that can drop a copy of additional malware on the device. Computer users vital information is also in danger once the system is infected with this virus. It is able to collect several data points, including username, password, IP address, ISP, network setup, and computer configuration. If TrojanSpy:MSIL/AgentTesla is identified on the computer, it denotes that a more hazardous virus is about to infiltrate the system, and therefore, the user must perform an anti-virus scan immediately to avoid any further contamination.

How does it infect the computer?

TrojanSpy:MSIL/AgentTesla can reach random targets over the internet using different modules of propagation. It can carry out the attack via spam emails, malicious advertisements, bogus software updates, dubious software installers, social engineering attacks, and web injections. The latter payload carrier is running a script that automatically initiates the TrojanSpy:MSIL/AgentTesla infection through a malicious script that exploits certain software vulnerabilities in order to brute force its entry.

As soon as TrojanSpy:MSIL/AgentTesla is executed on the computer, it makes a copy of itself in the System folder of Windows. The virus also demands that the operating system run the malicious code during boot-up, which can be done by adding an entry in the Windows registry. Once TrojanSpy:MSIL/AgentTesla becomes memory resident, it can conceal its operation by masking the malicious process as legitimate, and thus, it can evade detection.

How does this malware operate?

TrojanSpy:MSIL/AgentTesla aims to collect valuable information once it infects the computer. Aside from that, this virus may also perform other malicious tasks, including the following:

  • Communicate with the remote server to download additional malware.
  • Upload the collected data to the server.
  • Update the current virus infection.
  • Disable any computer security features like antivirus and firewalls.


A computer infected with TrojanSpy:MSIL/AgentTesla may exhibit various symptoms, including unexpected system slowdowns or sluggish performance. Users may notice unauthorized access to or control over their system, with files and sensitive information being accessed or manipulated without their consent. TrojanSpy:MSIL/AgentTesla often creates backdoors for other malicious activities, leading to unexpected network traffic or unusual internet behavior. Additionally, frequent system crashes or unexplained errors may occur, indicating the presence of TrojanSpy:MSIL/AgentTesla compromising the computer’s stability and security.

Versions of TrojanSpy:MSIL/AgentTesla
Version Name Alert Level Date Added
TrojanSpy:MSIL/AgentTesla!MTB Severe Nov. 14, 2019
TrojanSpy:MSIL/AgentTesla!MSR Severe Apr. 15, 2020
TrojanSpy:MSIL/AgentTesla.AP!rfn Severe May 16, 2020
TrojanSpy:MSIL/AgentTesla is also detected as:
Avast Win32:PWSX-gen [Trj]
BitDefender Trojan.GenericKD.39629892
DrWeb Trojan.Siggen17.47124
ESET-NOD32 Win32/PSW.Agent.OJQ
F-Secure Trojan.TR/Kryptik.gnnpd
Fortinet MSIL/Kryptik.AEVQ!tr
Kaspersky HEUR:Trojan.MSIL.Crypt.gen
Malwarebytes Malware.AI.3937411490
McAfee AgentTesla-FDFR!E59C2C3D0584
Panda Trj/WLT.G
Sophos Troj/Krypt-KP

For more help

TrojanSpy:MSIL/AgentTesla belongs to a group of spyware programs that endanger the online privacy and security of computer users. To view similar threats, please browse the Trojan Spy category.

How to remove TrojanSpy:MSIL/AgentTesla?

To totally remove TrojanSpy:MSIL/AgentTesla from the computer and get rid of relevant viruses and trojans, please execute the procedures as stated on this page. Make sure that you have completely scanned the system with the suggested malware removal tools and virus scanners.

Step 1 : Scan the PC with Combo Cleaner for Windows

Combo Cleaner is a trusted computer security and optimization tool equipped with a powerful virus and malware detection engine. This program can get rid of computer virus like TrojanSpy:MSIL/AgentTesla through this procedure.

1. Download the application from the following page:

2. Save the file to your preferred location.

3. Double-click the downloaded file CCSetup.exe and install with the default settings.

4. At the end of the setup process, click Finish to run Combo Cleaner.

5. The tool will update the database file; please wait for this process to complete.

6. To begin checking for threats like TrojanSpy:MSIL/AgentTesla, click on the Start Scan button. Wait for this scan to finish.

Screenshot of Combo Cleaner PC

7. At the end of the scan process, click on Remove all threats to delete TrojanSpy:MSIL/AgentTesla malware, including all malicious objects from the computer.

To fully optimize the features of antivirus and privacy scanners, users may have to upgrade to the premium version.

Please continue with the succeeding removal procedures if you are comfortable manually getting rid of the computer virus and malicious items linked to it.

Step 2 : Start Windows in Safe Mode With Networking

The method of running Windows in Safe Mode before running a virus scan is effective in getting rid of TrojanSpy:MSIL/AgentTesla. This process can prevent most viruses and malware from loading, making it easier to detect and remove them.

1. On the Windows Search bar, please type msconfig.

Screenshot of Win 11 Search

2. Select and open System Configutation on the list of found results.

3. Once you are in the System Configuration window, go to the Boot tab.

Screenshot of Msconfig Win 11

4. Under the Boot Options area, please check Safe Boot so that it starts in Safe Mode after restarting.

5. Next, select Network. This will allow Windows to boot in Safe Mode with Networking.

6. Lastly, click on Apply and OK to save the changes.

7. Please restart Windows.

Do not forget to restore the normal boot process of Windows after running the virus scan. Simply repeat the method above, and this time, uncheck the Safe Boot option to run Windows normally.

Step 3 : Run Sophos Home Virus Scanner

To remove TrojanSpy:MSIL/AgentTesla automatically, scanning the computer with this powerful virus and malware removal tool is recommended. This scanner does not just uncover known threats like viruses or malware; it is also effective in discovering harmful files associated to TrojanSpy:MSIL/AgentTesla.

1. Please click on the link below to download the program.

2. After downloading, locate the file SophosInstall.exe in the Downloads folder.

3. Install by double-clicking on the file.

4. If it prompts "Do you want to allow this app to make changes on your device?" please click Yes.

5. Next, it will display the Terms and Conditions page. Click the Install button to begin.

Screenshot of Terms by Sophos Home

6. Run the installation with the default settings. Please note that an internet connection is required in order to download important updates.

7. After finishing the installation, you must login to the dashboard. If you already have a Sophos account, please login. Otherwise, please enter your details and click on the Create Account button.

8. Once you are in the Sophos Home console, click the Scan button to start checking the computer for TrojanSpy:MSIL/AgentTesla components.

Screenshot of Sophos Home

9. Scanning may take a while; please wait for this process to finish.

10. After scanning the computer, Sophos Home will start cleaning or deleting files infected with TrojanSpy:MSIL/AgentTesla.

11. You may now close Sophos Home. The computer is now free from TrojanSpy:MSIL/AgentTesla, as well as associated malware and viruses.

After executing the above instructions, TrojanSpy:MSIL/AgentTesla should have been completely removed from the computer. If there are still signs of infection or the computer is displaying unusual behaviors, please continue with the remaining procedures.

Another alternative for Windows 10/11 users is to scan the computer with Microsoft Defender Offline. This will run a virus scan in the recovery environment.

Step 4 : Double Check with Windows Security Apps

Microsoft Windows has a built-in security application that you can use to double-check if your computer is still infected with TrojanSpy:MSIL/AgentTesla. For Windows 10/11 users, please run Windows Security.

Windows 10 / 11 Instructions:

Windows Security is a free tool that was built to help you remove TrojanSpy:MSIL/AgentTesla, viruses, and other malicious items from Windows 10/11 systems. Follow these procedures to scan your computer with the tool:

1. Tap or click the Search charm and search for Windows Security

2. Click Open to run the program.

Screenshot of Win 11 Search

3. On the Dashboard, click Virus and threat protection from the sidebar.

Screenshot of Win 11 Virus Protection

4. On the right panel, click on Scan Options to see different levels of checking the computer.

5. Next, please select Full Scan button.

Screenshot of Full Scan Win 11

6. Lastly, click on the Scan now button to start scanning for the presence of TrojanSpy:MSIL/AgentTesla. The process may take a while to complete.

7. After the scan, Delete/Quarantine identified threats, whether they were relevant to TrojanSpy:MSIL/AgentTesla or not. You may now restart Windows to complete the virus removal process.

For Windows 8.1 and Windows 7, you can scan the computer for free with the Microsoft Malicious Software Removal Tool (MSRT 64-Bit). It is a stand-alone virus scanner tool that targets prevalent malware groups.

About the author

2 thoughts on “TrojanSpy:MSIL/AgentTesla”

  1. Could i be getting false positives? While malware bytes does not scan it, and my windows defender does. I had the Phonzy Trojan and now a day later Tesla trojan.
    My malwarebytes didnt find the Tesla one. But my windows defender did.

  2. @K, if Windows Defender can detect it, you must use the same program to remove the threat. Also, make sure that both your MBAM and WD are up to date.

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