Trojan:Win32/Dynamer!ac is a threat identified by Microsoft Security Software. This is a typical malware that targets the core system of Windows in order to complete its tasks. Trojan:Win32/Dynamer!ac was made to execute a series of commands once it gets inside the system. It will gather data like system settings, Windows version, network configuration, and so on. Collected data will be sent to remote attacker for analysis.

Threat behavior


In general, system will get infected with Trojan:Win32/Dynamer!ac if malicious code is executed on the computer. Source of this trojan may vary due to the changing ways how it is deployed. Typically, spam email messages disguising as open letter from reputable institution are used to deceive recipients. Body of the message contains enticing phrases that tries to convince user into opening the attached file.

Malicious links from social media sites and instant messaging program are also seen as method used in distributing Trojan:Win32/Dynamer!ac. Illegally distributed software and media materials may also contain code that can lead to the infection of this malware.


In order to run itself on Windows start-up, Trojan:Win32/Dynamer!ac will make a copy of itself under system files. Then, registry entry is created to call the file on each Windows boot-up. Apart from that, this malware will also drop non-malicious files on various folders of the compromised PC.

Trojan:Win32/Dynamer!ac occasionally connects to a remote host to execute tasks like the following:

  • Notify attacker on the new infection
  • Sends gathered data from the infected computer
  • Download and execute additional files including an updated version of the Trojan
  • Accept command from a remote attacker


There is not much obvious symptom from this malware. Trojan:Win32/Dynamer!ac operates silently in the background. However, Microsoft Security Software may alert you on the presence of this Trojan.

How to remove Trojan:Win32/Dynamer!ac?

To totally remove Trojan:Win32/Dynamer!ac 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:Win32/Dynamer!ac Instantly

To instantly remove Trojan:Win32/Dynamer!ac, 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:Win32/Dynamer!ac 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:Win32/Dynamer!ac 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:Win32/Dynamer!ac. 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:Win32/Dynamer!ac virus.

Windows 8 / 10 Instructions:

Windows Defender is a free tool that was built help you remove Trojan:Win32/Dynamer!ac, 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:Win32/Dynamer!ac


2. On the Home tab, click Full under Scan Options. Click Scan now to start scanning for presence of Trojan:Win32/Dynamer!ac. The process may take a while to complete.


3. After the scan, delete/quarantine identified threats wether it is relevant to Trojan:Win32/Dynamer!ac 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:Win32/Dynamer!ac 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:Win32/Dynamer!ac 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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16 thoughts on “Trojan:Win32/Dynamer!ac”

  1. I have already used the Windows Defender. And well it went away for about a half hour then showed right back up it never really went away. any other Ideas. I am just about to the point of reloading the system.

  2. Same problem – I keep finding and deleting/ quarantining it with windows defender, but it keeps coming back. I also have Malwarebytes, so maybe I should give a full scan with both?

  3. @Raven, try to run full scan on the computer. Also, rebooting Windows in Safe Mode before running the scan may give you positive results.

  4. After using Windows Defender in Safe Mode, I ran Kaspersky TDSSKiller and it did not find the the virus so it does appear at this point that Defender did do its job (in Safe Mode).

  5. I have done 3 full scans with defender windows and every time I have quarantine and removed and it keeps coming back! What else can I do?

  6. Windows Defender is powerless against this. It has frozen 3 times for several hours each in the process of removing software from my laptop.

  7. David
    January 25, 2016

    After using Windows Defender in Safe Mode, I ran Kaspersky TDSSKiller and it did not find the the virus so it does appear at this point that Defender did do its job (in Safe Mode).

    Did any of you people got rid of this?

  8. Dynamer is relatively easy to remove by first killing the process with Task Manager and then running “rd “\\.\%appdata%\com4.{241D7C96-F8BF-4F85-B01F-E2B043341A4B}” /S /Q” in the command line.

  9. T3POX — sounds like you have the solution but I’m not very literate. What do you mean by “kill the process”? I went into task manager and cannot identify an appropriate program to kill.

  10. I have done 4 or 5 times full scans with defender windows and every time I have quarantine and removed and it keeps coming back! What else can I do?

  11. T3POX I entered in the command prompt your suggestion but get error is not recognized as an internal or external command, operable program or batch file. Any thoughts?

  12. I have run Windows defender twice and it keeps on finding Trojan Dynamer even after removal… what next for me?

  13. I removed it from mine ,,, first before you even start the windows defender scan , only defender can remove it ..
    windows 10 I have , but it should work the same on any other ,
    OPEN task manager go to services , find volume shadow copy IT MUST BE RUNNING OK .. DO NOT CLOSE THAT WINDOW
    it MUST stay open ..
    then start the defender scan once the scan is finished make Shure the volume shadow is still running if u close that window it might stop ,it needs to be running ,
    then get defender to remove it ,
    it should work first time but could take 3 times though it worked for me and it took me ages to work this out , hope it helps you ..

  14. vince ciarametaro

    I tried Craig Kasch method, not only did it not work it made things worse.

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