Remove Win32:Malware-gen trojan (Removal Guide)

Win32.Malware-Gen refers to a range of malware applications that infect computers running a 32-bit version of the Windows operating system. Depending on which version of Win32.Malware-Gen your computer is infected with, the virus may download and install other viruses, monitor computer activities, log keystrokes or corrupt your system registry and files.

Win32:Malware-gen is the generic description from Avira, Microsoft, Avast and ESET of unknown Trojans which are detected by its antivirus heuristic engine.
[Image: Win32:Malware-gen]
Win32:Malware-gen trojan is distributed through several means. Malicious websites, or legitimate websites that have been compromised, may drop this trojan onto a compromised computer. This drive-by-download often happens surreptitiously. Another method used to propagate this type of malware is spam email containing infected attachments or links to malicious websites. The threat may also be downloaded manually by tricking the user into thinking they are installing a useful piece of software.
Win32:Malware-gen virus is also prevalent on peer-to-peer file sharing websites and is often packaged with pirated or illegally acquired software.

Win32:Malware-gen is a type of trojan that installs itself to the system and waits until an Internet connection becomes available to connect to a remote server or website in order to download additional programs (usually malware) onto the infected computer.
Once its primary download/execution routine is completed, it may also proceed to a secondary payload routine.
There are several different files that the various versions of Win32.Malware-Gen are known to infect, including a number of Windows system files. Infected executable EXE files include, but are not limited to, wmiprsv.exe, svchhost.exe, msblast.exe, taskmon.exe, winsys.exe, d3dupdate.exe and sysinfo.exe. The worm is also known to infect the sfc_os.dll dynamic-link library file.

If your antivirus has detected any variant of the Win32:Malware-gen virus, you should quarantine this infection (by selecting “Move to quarantine“), and following the below removal guide.

Win32:Malware-gen – Virus Removal Instructions

STEP 1:  Remove Win32:Malware-gen infection with Kaspersky TDSSKiller

As part of its self defense mechanism, Win32:Malware-gen will install a rootkit on the infected computer.In this first step, we will run a system scan with Kaspersky TDSSKiller to remove this rookit.

  1. Please download the latest official version of Kaspersky TDSSKiller.
    KASPERSKY TDSSKILLER DOWNLOAD LINK(This link will automatically download Kaspersky TDSSKiller on your computer.)
  2. Before you can run Kaspersky TDSSKiller, you first need to rename it so that
    you can get it to run. To do this, right-click on the TDSSKiller.exe icon and select Rename.
    Edit the name of the file from TDSSKiller.exe to iexplore.exe, and then double-click on it to launch.
  3. Kaspersky TDSSKiller will now start and display the welcome screen and we will need to click on Change Parameters.
    Kaspersky TDSSKiller change settings
  4. In the new open window,we will need to enable Detect TDLFS file system, then click on OK.
    Kaspersky TDSSKiller Detect TDLFS file system
  5. Next,we will need to start a scan with Kaspersky, so you’ll need to press the Start Scan button.
    Kaspersky TDSSKiller start scan
  6. Kaspersky TDSSKiller will now scan your computer for Win32:Malware-gen infection.
    Kaspersky TDSSKiller scan
  7. When the scan has finished it will display a result screen stating whether or not the infection was found on your computer. If it was found it will display a screen similar to the one below.
    Kaspersky TDSSKiller results
  8. To remove the infection simply click on the Continue button and TDSSKiller will attempt to clean the infection.A reboot will be require to completely remove any infection from your system.

STEP 2 : Remove any ZeroAccess rootkit dropped by Win32:Malware-gen with Combofix

Win32:Malware-gen may infect your machine with a Trojan ZeroAccess rootkit, so we will need to run Combofix to remove this malicious program.

  1. Download Combofix from any of the below links.
    COMBOFIX DOWNLOAD LINK #1 (This link will automatically download Combofix on your computer)
    COMBOFIX DOWNLOAD LINK #2  (This link will automatically download Combofix on your computer)
  2. Before running this utiltiy,please follow the below instructions:
    • Close any open browsers.
    • Close/disable all anti virus and anti malware programs so they do not interfere with the running of ComboFix.
      Temporarily disable your anti-virusscript blocking and any anti-malware real-time protection beforeperforming a scan. They can interfere with ComboFix or remove some of its embedded files which may cause “unpredictable results”.
    • WARNING: Combofix will disconnect your machine from the Internet as soon as it starts
      Please do not attempt to re-connect your machine back to the Internet until Combofix has completely finished.
      If there is no internet connection after running Combofix, then restart your computer to restore back your connection.
  3. Start the Combofix scan:
    1. Double click on ComboFix.exe and then follow the prompts.
    2. Accept the disclaimer and allow to update if it asks.
    3. When finished, it shall produce a log for you.
    4. Restart your computer

    Additional Notes:

    • DO NOT mouse-click Combofix’s window while it is running. That may cause it to stall.
    • DO NOT “re-run” Combofix. If you have a problem, reply back for further instructions.
    • IF after the reboot you get errors about programs being marked for deletion then reboot, that will cure it.

STEP 3: Remove Win32:Malware-gen malicious files with Malwarebytes Anti-Malware

Malwarebytes Chameleon technologies will allow us to install and run a Malwarebytes Anti-Malware scan without being blocked by Win32:Malware-gen.

  1. Download Malwarebytes Chameleon from the below link and extract it to a folder in a convenient location.
    MALWAREBYTES CHAMELEON DOWNLOAD LINK  (This link will open a new web page from where you can download Malwarebytes Chameleon)
  2. Make certain that your infected computer is connected to the internet and then open the Malwarebytes Chameleon folder and double-click on svchost.exe.
    Malwarebytes Chameleon
    IF Malwarebytes Chameleon will not open, double-click on the other renamed files until you find one will work, which will be indicated by a black DOS/command prompt window.
  3. Follow the onscreen instructions to press a key to continue and Chameleon will proceed to download and install Malwarebytes Anti-Malware for you.
    Malwarebytes Chameleon press key
  4. Once it has done this, it will update Malwarebytes Anti-Malware, and you’ll need to click OK when it says that the database was updated successfully.
    Malwarebytes Chameleon updating its database
  5. Malwarebytes Anti-Malware will now attempt to kill all the malicious process associated with Win32:Malware-gen.Please be aware that this process can take up to 10 minutes, so please be patient.
    Malwarebytes Chameleon killing malware
  6. Next, Malwarebytes Anti-Malware will automatically open and perform a Quick scan for Win32:Malware-gen malicious files as shown below.
    [Image: Malwarebytes Anti-Malware scanning for Win32:Malware-gen]
  7. Upon completion of the scan, click on Show Result
    [Image: Malwarebytes Anti-Malware scan results]
  8. You will now be presented with a screen showing you the malware infections that Malwarebytes Anti-Malware has detected.
    Make sure that everything is Checked (ticked),then click on the Remove Selected button.
    [Image:Malwarebytes removing virus]
  9. After your computer restarts, open Malwarebytes Anti-Malware and perform a Full System scan to verify that there are no remaining threats

STEP 4 : Remove the malicious registry keys added by the Win32:Malware-gen

Win32:Malware-gen has added some malicious registry keys to your Windows installation,to remove them we will need to perform a scan with RogueKiller.

  1. You can download RogueKiller from the below link.
    ROGUEKILLER DOWNLOAD LINK (This link will automatically download RogueKiller on your computer)
  2. Double click on RogueKiller.exe to start this utility and then wait for the Prescan to complete.This should take only a few seconds and then you can click the Start button to perform a system scan.
    [Image: RogueKiller while scanning]
  3. After the scan has completed, press the Delete button to remove any malicious registry keys.
    [Image: RogueKiller removing Win32:Malware-gen]

STEP 5: Remove Win32:Malware-gen rootkit with HitmanPro

  1. you can download HitmanPro from the below link,then double click on it to start this program.
    HITMANPRO DOWNLOAD LINK (This link will open a new web page from where you can download HitmanPro)
    IF you are experiencing problems while trying to start HitmanPro, you can use the Force Breach mode.To start HitmanPro in Force Breach mode, hold down the left CTRL-key when you start HitmanPro and all non-essential processes are terminated, including the malware process. (How to start HitmanPro in Force Breach mode – Video)
  2. HitmanPro will start and you’ll need to follow the prompts (by clicking on the Next button) to start a system scan with this program.
    HitmanPro scanner
    HitmanPro installation
  3. HitmanPro will start scanning your computer for Win32:Malware-gen malicious files as seen in the image below.
    HitmanPro scan after Win 7 Defender
  4. Once the scan is complete,you’ll see a screen which will display all the infected files that this utility has detected, and you’ll need to click on Next to remove this malicious files.
    HitmanPro scan results
  5. Click Activate free license to start the free 30 days trial and remove all the malicious files from your computer.
    HitmanPro 30 days activation button

STEP 6: Double check for any left over infections with Emsisoft Emergency Kit

  1. You can download Emsisoft Emergency Kit from the below link,then extract it to a folder in a convenient location.
    EMSISOFT EMERGENCY KIT DOWNLOAD LINK ((This link will open a new web page from where you can download Emsisoft Emergency Kit)
  2. Open the Emsisoft Emergency Kit folder and double click EmergencyKitScanner.bat, then allow this program to update itself.
    EmergencyKitScanner.bat file
  3. After the Emsisoft Emergency Kit has update has completed,click on the Menu tab,then select Scan PC.
    Emsisoft Emergency Kit scan tab
  4. Select Smart scan and click on the SCAN button to search for Win32:Malware-gen malicious files.
    Emsisoft Emergency Kit smart scan
  5. When the scan will be completed,you will be presented with a screen reporting which malicious files has Emsisoft detected on your computer, and you’ll need to click on Quarantine selected objects to remove them.
    Emsisoft Emergency Kit removing malware

STEP 6: Double check for any left over infections on your computer

If want to make another check for any left over malicious files, you can run a scan with the following tools:

STEP A: Run a scan with Eset Online Scanner.

  1. Download ESET Online Scanner utility.
    ESET Online Scanner Download Link (This link will automatically download ESET Online Scanner on your computer.)
  2. Double click on the Eset installer program (esetsmartinstaller_enu.exe).
  3. Check Yes, I accept the Terms of Use
  4. Click the Start button.
  5. Check Scan archives
  6. Push the Start button.
  7. ESET will then download updates for itself, install itself, and begin scanning your computer. Please be patient as this can take some time.
  8. When the scan completes, push Finish

STEP B: Run a scan with Emsisoft Emergency Kit.

  1. Please download the latest official version of Emsisoft Emergency Kit.
    EMSISOFT EMERGENCY KIT DOWNLOAD LINK (This link will open a download page in a new window from where you can download Emsisoft Emergency Kit)
  2. After the download process will finish , you’ll need to unpack EmsisoftEmergencyKit.zip and then double click on EmergencyKitScanner.bat
  3. A pop-up will prompt you to update Emsisoft Emergency Kit , please click the “Yes” button.After the Update process has completed , put the mouse cursor over the “Menu” tab on the left and click-on “Scan PC“.
  4. Select “Smart scan” and click-on the below “SCAN” button.When the scan will be completed , you will be presented with a screen showing you the malware infections that Emsisoft Emergency Kit has detected.Make sure that everything is Checked (ticked) and click on the ‘Quarantine selected objects‘ button.

Next,we will remove Combofix from your machine and in addition, you can uninstall any of the tools that we’ve used:

Lets remove ComboFix from your computer:

  1. Hold down the Windows key + R on your keyboard. This will display the Run dialogue box
  2. In the Run box, type in ComboFix /Uninstall (Notice the space between the “x” and “/”) then click OK Combofix uninstall command
  3. Follow the prompts on the screen
  4. A message should appear confirming that ComboFix was uninstalled

Delete the following files: (If they exist)
C:\ComboFix.txt

Delete the following folders: (If they exist)
C:\ComboFix
C:\Qoobox
ESET Online Scanner, Emsisoft Emergency Kit, Kaspersky TDSSKiller and RogueKiller can be removed by right clicking on their icons, and selecting Delete.
We strongly recommend that you keep Malwarebytes Anti-Malware and HitmanPro installed on your machine and perform regular scans with these on-demand scanners. However if you wish to remove them, you can go into the Add/Remove Programs and uninstall these two utilities.

If you are still experiencing problems while trying to remove ZeroAccess trojan from your machine, please start a new thread in our Malware Removal Assistance forum.

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ABOUT STELIAN PILICI

I am the creator and owner of MalwareTips.com.
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 (Romania), where I run my own local computer repair shop.
I repair both hardware and other operating systems related issues, however most of my business is malware related problems.

You can follow me on Google+ , and I will keep you up-to-date with the latest computer infections and malware threats.

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  • Braveler

    A wonderful public service. Tnx so much!

  • Corina

    All I can say is my computer has never been soooooo clean. You absolutely rock!

  • Bojidar Samokovski

    Ty man u saved me :3