Remove Trojan:Win32/Dynamer!ac malware (Virus Removal Guide)

Trojan:Win32/Dynamer!ac is a generic detection used by Windows Defenderfor a file that appears to have trojan-like features or behavior.
Trojan:Win32/Dynamer!ac contains malicious or potentially unwanted software which downloads and installs on the affected system. Commonly, this infection will install a backdoor which allows remote, surreptitious access to infected systems. This backdoor may then be used by remote attackers to upload and install further malicious or potentially unwanted software on the system.

What is the Trojan:Win32/Dynamer!ac infection?

Trojan:Win32/Dynamer!ac is a trojan that silently downloads and installs other programs without consent. This could include the installation of additional malware or malware components to an affected computer.

Trojan:Win32/Dynamer!ac is a is a broad classification used by Windows Defender for a file that appears to have trojan-like features or behavior for software that exhibits suspicious behavior categorized as potentially malicious.
The Behavior Monitoring feature observes the behavior of processes as they run programs. If it observes a process behaving in a potentially malicious way, it reports the program the process is running as potentially malicious.

Due to the generic nature of this detection, methods of installation may vary. The Trojan:Win32/Dynamer!ac infections may often install themselves by copying their executable to the Windows or Windows system folders, and then modifying the registry to run this file at each system start. Trojan:Win32/Dynamer!acwill often modify the following subkey in order to accomplish this:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

Trojan:Win32/Dynamer!ac may contact a remote host at opencapture.co.kr using port 80. Commonly, malware may contact a remote host for the following purposes:

  • To report a new infection to its author
  • To receive configuration or other data
  • To download and execute arbitrary files (including updates or additional malware)
  • To receive instruction from a remote attacker
  • To upload data taken from the affected computer

Is Trojan:Win32/Dynamer!ac a False Positive ?

Files reported as Trojan:Win32/Dynamer!ac are not necessarily malicious. For example, users can be tricked into using non-malicious programs, such as Web browsers, to unknowingly perform malicious actions, such as downloading malware. Some otherwise harmless programs may have flaws that malware or attackers can exploit to perform malicious actions.

Should you be uncertain as to whether a file has been reported correctly, we encourage you to submit the affected file to https://www.virustotal.com/en/ to be scanned with multiple antivirus engines.

How did Trojan:Win32/Dynamer!ac infection got on my computer?

The Trojan:Win32/Dynamer!ac virus is distributed through several means. Malicious websites, or legitimate websites that have been hacked, can infect your machine through exploit kits that use vulnerabilities on your computer to install this Trojan without your permission of knowledge.

Another method used to propagate this type of malware is spam email containing infected attachments or links to malicious websites. Cyber-criminals spam out an email, with forged header information, tricking you into believing that it is from a shipping company like DHL or FedEx. The email tells you that they tried to deliver a package to you, but failed for some reason. Sometimes the emails claim to be notifications of a shipment you have made. Either way, you can’t resist being curious as to what the email is referring to – and open the attached file (or click on a link embedded inside the email). And with that, your computer is infected with the Trojan:Win32/Dynamer!ac virus.

The threat may also be downloaded manually by tricking the user into thinking they are installing a useful piece of software, for instance a bogus update for Adobe Flash Player or another piece of software.

How to remove Trojan:Win32/Dynamer!ac (Removal Guide)

This page is a comprehensive guide which will remove Trojan:Win32/Dynamer!ac from Windows.
Please perform all the steps in the correct order. If you have any questions or doubt at any point, STOP and ask for our assistance.

STEP 1: Scan your computer with Malwarebytes AdwCleaner

Malwarebytes AdwCleaner is a free utility that will scan your computer for adware programs that may have been installed without your knowledge.

  1. You can download Malwarebytes AdwCleaner from the below link.
    MALWAREBYTES ADWCLEANER DOWNLOAD LINK (This link will start the download of “Malwarebytes AdwCleaner” on your computer)
  2. Before starting Malwarebytes AdwCleaner, close your web browser, then double-click on the Malwarebytes AdwCleaner icon.
    Open Malwarebytes AdwCleaner
    If Windows prompts you as to whether or not you wish to run Malwarebytes AdwCleaner, please allow it to run.
    Windows asking permission to start Malwarebytes AdwCleaner
  3. When the Malwarebytes AdwCleaner program will open, click on the “Scan” button as shown below.
    Scan your computer with Malwarebytes AdwCleaner to remove adware
    Malwarebytes AdwCleaner will now start to search for the Trojan:Win32/Dynamer!ac adware and other malicious programs.
  4. To remove the malicious files that were detected in the previous step, please click on the “Clean” button.
    Malwarebytes AdwCleaner removing Adware
  5. Malwarebytes AdwCleaner will prompt you to save any open files or documents, as the program will need to reboot the computer to complete the cleaning process. Please do so, and then click on the “OK” button.
    Malwarebytes AdwCleaner finishing malware removal
    When your computer reboots and you are logged in, Malwarebytes AdwCleaner will automatically open a log file that contains the files, registry keys, and programs that were removed from your computer. Please review this log file and then close the notepad window.

STEP 2: Scan your computer with Malwarebytes Anti-Malware

Malwarebytes Anti-Malware is a powerful on-demand scanner which will remove the Trojan:Win32/Dynamer!ac malware from your machine. It is important to note that Malwarebytes Anti-Malware will run alongside antivirus software without conflicts.

  1. You can download download Malwarebytes Anti-Malware from the below link.
    MALWAREBYTES ANTI-MALWARE DOWNLOAD LINK (This link will open a new web page from where you can download “Malwarebytes Anti-Malware”)
  2. Once downloaded, close all programs, then double-click on the icon on your desktop named “mbam-setup” to start the installation of Malwarebytes Anti-Malware.
    Malwarebytes Anti-Malware Icon
    You may be presented with a User Account Control dialog asking you if you want to run this file. If this happens, you should click “Yes” to continue with the installation.
    Windows asking permission to install Malwarebytes
  3. When the installation begins, you will see the Malwarebytes Anti-Malware Setup Wizard which will guide you through the installation process.
    Malwarebytes Anti-Malware Setup Wizard
    To install Malwarebytes Anti-Malware on your machine, keep following the prompts by clicking the “Next” button.
    Malwarebytes Anti-Malware setup wizard
  4. Once installed, Malwarebytes Anti-Malware will automatically start and will update the antivirus database. To start a system scan you can click on the “Scan Now” button.
    Start a scan with Malwarebytes scan
  5. Malwarebytes Anti-Malware will now start scanning your computer for the Trojan:Win32/Dynamer!ac browser hijacker. When Malwarebytes Anti-Malware is scanning it will look like the image below.
    Malwarebytes Anti-Malware scanning for malware
  6. When the scan has completed, you will be presented with a screen showing the malware infections that Malwarebytes Anti-Malware has detected. To remove the malicious programs that Malwarebytes Anti-malware has found, click on the “Remove Selected” button.
    To remove malware click on the Remove Selected button
  7. Malwarebytes Anti-Malware will now quarantine all the malicious files and registry keys that it has found. When removing the files, Malwarebytes Anti-Malware may require a reboot in order to remove some of them. If it displays a message stating that it needs to reboot your computer, please allow it to do so.

STEP 3: Scan your computer with HitmanPro

HitmanPro finds and removes malware, adware, bots and other threats that even the best antivirus suite can oftentimes miss. It’s designed to run alongside your antivirus suite, firewall and other security tools.

  1. You can download HitmanPro from the below link:
    HITMANPRO DOWNLOAD LINK (This link will open a new web page from where you can download “HitmanPro”)
  2. Double-click on the file named “HitmanPro.exe” (for 32-bit versions of Windows) or “HitmanPro_x64.exe” (for 64-bit versions of Windows).
    HitmanPro Icon
    Click on the “Next” button, to install HitmanPro on your computer.
    HitmanPro setup process
  3. HitmanPro will now begin to scan your computer for malware.
    HitmanPro scanning for Trojan:Win32/Dynamer!ac virus
  4. When it has finished it will display a list of all the malware that the program found as shown in the image below. Click on the “Next” button, to remove malware.
    HitmanPro detected malware
  5. Click on the “Activate free license” button to begin the free 30 days trial and remove all the malicious files from your computer.
    Activate HitmanPro to remove malware

(OPTIONAL) STEP 4: Scan your computer with Zemana AntiMalware

Zemana AntiMalware is a powerful utility which will remove Trojan:Win32/Dynamer!ac malware and other malware from your machine.
This step should be performed only if your issues have not been solved by the previous steps.
  1. You can download Zemana AntiMalware from the below link:
    ZEMANA ANTIMALWARE DOWNLOAD LINK (This link will start the download of “Zemana AntiMalware”)
  2. Double-click on the file named “Zemana.AntiMalware.Setup.exe” to start the installation of Zemana AntiMalware.
    Double-click on the Zemana AntiMalware to instal it
    You may be presented with a User Account Control dialog asking you if you want to run this file. If this happens, you should click “Yes” to continue with the installation.
    Zemana AntiMalware UAC
  3. Click on the “Next” button, to install Zemana AntiMalware on your computer.
    Zemana AntiMalware installation
    When you reach the “Select Additional Tasks” screen, you can opt-out the “Enable Real Time Protection” option, then click on the “Next” button.
    Opt-out of the real-time protection feature
  4. When Zemana AntiMalware will start, click on the “Scan” button.
    Scan computer with Zemana AntiMalware
  5. Zemana AntiMalware will now scan computer for malicious files. This process can take up to 10 minutes.
    Zemana AntiMalware performing a scan
  6. When Zemana AntiMalware has finished it will display a list of all the malware that the program found. Click on the “Next” button, to remove the malicious files from your computer.
    Zemana AntiMalware removing malware
    Zemana AntiMalware will now remove all the detected malicious files and at the end a system reboot may be required to remove all traces of malware.

(OPTIONAL) STEP 5: Reset your browser to default settings

If you are still experiencing issues with the Trojan:Win32/Dynamer!ac browser hijacker in Internet Explorer, Firefox or Chrome, we will need to reset your browser to its default settings.
This step should be performed only if your issues have not been solved by the previous steps.

Google Chrome


Google Chrome has an option that will reset itself to its default settings. Resetting your browser settings will reset the unwanted changes caused by installing other programmes. However, your saved bookmarks and passwords will not be cleared or changed.

  1. Click on Chrome’s main menu button, represented by three horizontal lines. When the drop-down menu appears, select the option labeled Settings.
    Google Chrome Settings button
  2. Chrome’s Settings should now be displayed in a new tab or window, depending on your configuration. Next, scroll to the bottom of the page and click on the Show advanced settings link (as seen in the below example).
    Google Chrome Advanced Settings
  3. Chrome’s advanced Settings should now be displayed. Scroll down until the Reset browser settings section is visible, as shown in the example below. Next, click on the Reset browser settings button.
    Google Chrome Reset button
  4. A confirmation dialog should now be displayed, detailing the components that will be restored to their default state should you continue on with the reset process. To complete the restoration process, click on the Reset button.
    Reset Google Chrome settings

Internet Explorer


You can reset Internet Explorer settings to return them to the state they were in when Internet Explorer was first installed on your PC.

  1. Open Internet Explorer, click on the “gear iconIE Icon Gear in the upper right part of your browser, then click again on Internet Options.
    [Image: Internet Options in Internet Explorer]
  2. In the “Internet Options” dialog box, click on the “Advanced” tab, then click on the “Reset” button.
    [Image: Reset Internet Explorer]
  3. In the “Reset Internet Explorer settings” section, select the “Delete personal settings” check box, then click on “Reset” button.
    [Image: Reset Internet Explorer to its default settings]
  4. When Internet Explorer has completed its task, click on the “Close” button in the confirmation dialogue box. You will now  need to close your browser and then you can open Internet Explorer again.
    [Image Reset Internet Explorer settings]

Mozilla Firefox


If you’re having problems with Firefox, resetting it can help. The reset feature fixes many issues by restoring Firefox to its factory default state while saving your essential information like bookmarks, passwords, web form auto-fill information, browsing history and open tabs.

  1. In the upper-right corner of the Firefox window, click the Firefox menu button ([Image: Firefox Menu button]), then click on the “Help” ([Image: Firefox Help button]) button.
    Firefox Help button
  2. From the Help menu, choose Troubleshooting Information.
    If you’re unable to access the Help menu, type about:support in your address bar to bring up the Troubleshooting information page.
    Troubleshooting Information in Firefox
  3. Click the “Refresh Firefox” button in the upper-right corner of the “Troubleshooting Information” page.
    Refresh Firefox button
  4. To continue, click on the “Refresh Firefox” button in the new confirmation window that opens.
    Reset Firefox settings to default
  5. Firefox will close itself and will revert to its default settings. When it’s done, a window will list the information that was imported. Click on the “Finish“.
Your old Firefox profile will be placed on your desktop in a folder named “Old Firefox Data“. If the reset didn’t fix your problem you can restore some of the information not saved by copying files to the new profile that was created. If you don’t need this folder any longer, you should delete it as it contains sensitive information.

Your computer should now be free of the Trojan:Win32/Dynamer!ac browser hijacker. You can remove AdwCleaner from your machine, however we recommend that you keep Malwarebytes Anti-Malware and HitmanPro installed and perform regular computer scans.

If you are still experiencing problems while trying to remove Trojan:Win32/Dynamer!ac malware, please ask for help in our Malware Removal Assistance forum.

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I am the creator and owner of the MalwareTips Community. I've started this site in 2010 to help people solve their computer problems. My area of expertise includes malware removal and computer forensics. I'm active in the various online anti-malware communities where I do researches for new malware threats as they are released. I live in Bucharest, where I run my own local computer repair shop. You can follow me on Google+ and I will keep you up-to-date with the latest computer infections and malware threats.