Antivirus .NET is a rogue anti-spyware program from the same family as Antivirus Scan . When this infection is installed on your computer it will be configured to start automatically. Once started it will scan your computer and list numerous infections in the scan results. If you attempt to remove any of these so-called infections it will state that you first need to purchase the program in order to remove anything. As these scan results are all fake, please do not purchase this program based upon anything it states.

 

Antivirus .Net
For more screen shots of this infection click on the image above.
There are a total of 4 images you can view.

 

To protect itself, Antivirus .NET will terminate most executables that you attempt to run. It does this to prevent you from running any security applications that may be able to remove the infection. When the rogue terminates the program it will display an alert stating that the program is infected. The text of this alert is:

Security Warning
Application cannot be executed. The file defrag.exe is infected. Do you want to activate your antivirus software now?

This alert should be ignored as the files you are attempting are not actually infected.

While running, Antivirus .NET will also display fake security alerts on your computer. These security alerts are used to make you think that there are various security problems on your computer. The text of some of these alerts include:

Windows Security Alert
Windows reports that computer is infected. Antivirus software helps to protect your computer against viruses and other security threats. Click here for the scan your computer. Your system might be at risk now.

Antivirus software alert
Infiltration alert
Your computer is being attacked by an Internet virus. It could be password-stealing attack, a trojan-dropper or similar.

Antivirus .NET will also configure your computer to use a proxy server so that it hijackthis your web browser to display warnings when you browse the web. This warning is:

Internet Explorer Warning - visiting this web site may harm your computer!
Most likely causes:
- The website contains exploits that can launch a malicious code on your computer
- Suspicious network activity detected
- There might be an active spyware running on your computer

Just like the fake scan results, these fake alerts and browser hijack messages are just another tactic to have you purchase the program.

As you can see, the warnings issued by this program are all fake, and once you realize that, the alerts become more of a nuisance rather than a concern. Therefore, do not purchase Antivirus .NET for any reason, and if you already have, please contact your credit card company and state that the program is a computer infection and a scam and that you would like to dispute the charge. To remove this infection and related malware, please follow the steps in the guide below.

 

Threat Classification:

• Information on Rogue Programs & Scareware

 

Advanced information:

View Antivirus .NET files.
View Antivirus .NET Registry Information.

 

Tools Needed for this fix:

• Malwarebytes Anti-Malware

 

Symptoms that may be in a HijackThis Log:

R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyServer = http=http=127.0.0.1:8992
O4 - HKCU\..\Run: [<random>] %Temp%\<random>\<random>.exe

 

Guide Updates:

01/27/11 - Initial guide creation.
02/09/11 - Fixed some mistakes in the formatting.
02/13/11 - Updated instructions to remove the Proxy server.

 

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Automated Removal Instructions for Antivirus .NET using Malwarebytes Anti-Malware:

 

1. Print out these instructions as we may need to close every window that is open later in the fix.
   
   
2. It is possible that the infection you are trying to remove will not allow you to download files on the infected computer. If you run into this problem when following the steps in this guide you will need to download the files requested in this guide on another computer and then transfer them to the infected computer. You can transfer the files via a CD/DVD, external drive, or USB flash drive.
   
   
3. Reboot your computer into Safe Mode with Networking using the instructions for your version of Windows found in the following tutorial:
   

   How to start Windows in Safe Mode

   When following the steps in the above tutorial, select Safe Mode with Networking rather than just Safe Mode. When the computer reboots into Safe Mode with Networking make sure you login with the username you normally use. When you are at your Windows desktop, please continue with the rest of the steps.
   
   
4. This infection changes your Windows settings to use a proxy server that will not allow you to browse any pages on the Internet with Internet Explorer or update security software. Regardless of the web browser you use, for these instructions we will first need need to fix this problem so that we can download the utilities we need to remove this infection.
   
   Please start Internet Explorer, and when the program is open, click on the Tools menu and then select Internet Options as shown in the image below.
   
   
   
   
   
   
   
   
5. You should now be in the Internet Options screen as shown in the image below.
   
   
   
   
   
   
   
   
   Now click on the Connections tab as designated by the blue arrow above.
   
   
6. You will now be at the Connections tab as shown by the image below.
   
   
   
   
   
   
   
   Now click on the Lan Settings button as designated by the blue arrow above.
   
   
7. You will now be at the Local Area Network (LAN) settings screen as shown by the image below.
   
   
   
   
   
   
   
   
   Under the Proxy Server section, please uncheck the checkbox labeled Use a proxy server for your LAN. Then press the OK button to close this screen. Then press the OK button to close the Internet Options screen. Now that you have disabled the proxy server you will be able to browse the web again with Internet Explorer.
   
   
8. Now we must end the processes that belong to Antivirus .NET so that it does not interfere with the cleaning procedure. To do this, please download RKill to your desktop from the following link.
   
   RKill Download Link - (Download page will open in a new tab or browser window.)
   
   When at the download page, click on the Download Now button labeled iExplore.exe download link. When you are prompted where to save it, please save it on your desktop.
   
   If you are unable to connect to the site to download RKill, please go back and do steps 3-6 again and make sure the infection has not reenabled the proxy settings. You may have to do this quite a few times before you can get RKill downloaded. If you still cannot download the RKill program on the infected computer, you should download it to a clean computer and copy it to the infected one via a USB flash drive or CDROM.
   
   
9. Once it is downloaded, double-click on the iExplore.exe icon in order to automatically attempt to stop any processes associated with Antivirus .NET and other Rogue programs. Please be patient while the program looks for various malware programs and ends them. When it has finished, the black window will automatically close and you can continue with the next step. If you get a message that RKill is an infection, do not be concerned. This message is just a fake warning given by Antivirus .NET when it terminates programs that may potentially remove it. If you run into these infections warnings that close RKill, a trick is to leave the warning on the screen and then run RKill again. By not closing the warning, this typically will allow you to bypass the malware trying to protect itself so that RKill can terminate Antivirus .NET . So, please try running RKill until the malware is no longer running. You will then be able to proceed with the rest of the guide. Do not reboot your computer after running RKill as the malware programs will start again.
   
   If you continue having problems running RKill, you can download the other renamed versions of RKill from the RKill download page. Both of these files are renamed copies of RKill, which you can try instead. Please note that the download page will open in a new browser window or tab.
   
   
10. Now you should download Malwarebytes Anti-Malware, or MBAM, from the following location and save it to your desktop:
    
    Malwarebytes Anti-Malware Download Link (Download page will open in a new window)
    
    If you are unable to connect to the site to download Malwarebytes', please go back and do steps 3-6 again and make sure the infection has not reenabled the proxy settings.
    
    


11. Once downloaded, close all programs and Windows on your computer, including this one.
    
    
12. Double-click on the icon on your desktop named mbam-setup.exe. This will start the installation of MBAM onto your computer.
    
    
13. When the installation begins, keep following the prompts in order to continue with the installation process. Do not make any changes to default settings and when the program has finished installing, make sure you leave both the Update Malwarebytes Anti-Malware and Launch Malwarebytes Anti-Malware checked. Then click on the Finish button. If MalwareBytes' prompts you to reboot, please do not do so.
    
    
14. MBAM will now automatically start and you will see a message stating that you should update the program before performing a scan. As MBAM will automatically update itself after the install, you can press the OK button to close that box and you will now be at the main program as shown below.
    
    
    
    
    
    
    
15. On the Scanner tab, make sure the the Perform full scan option is selected and then click on the Scan button to start scanning your computer for Antivirus .NET related files.
    
    
16. MBAM will now start scanning your computer for malware. This process can take quite a while, so we suggest you go and do something else and periodically check on the status of the scan. When MBAM is scanning it will look like the image below.
    
    
    
    
    
    
    
17. When the scan is finished a message box will appear as shown in the image below.
    
    
    
    
    
    
    You should click on the OK button to close the message box and continue with the Antivirus .NET removal process.
    
    
18. You will now be back at the main Scanner screen. At this point you should click on the Show Results button.
    
    
19. A screen displaying all the malware that the program found will be shown as seen in the image below. Please note that the infections found may be different than what is shown in the image.
    
    
    
    
    
    
    
    You should now click on the Remove Selected button to remove all the listed malware. MBAM will now delete all of the files and registry keys and add them to the programs quarantine. When removing the files, MBAM may require a reboot in order to remove some of them. If it displays a message stating that it needs to reboot, please allow it to do so. Once your computer has rebooted, and you are logged in, please continue with the rest of the steps.
    
    
20. When MBAM has finished removing the malware, it will open the scan log and display it in Notepad. Review the log as desired, and then close the Notepad window.
    
    
21. You can now exit the MBAM program.
    
    
22. As many rogues and other malware are installed through vulnerabilities found in out-dated and insecure programs, it is strongly suggested that you use Secunia PSI to scan for vulnerable programs on your computer. A tutorial on how to use Secunia PSI to scan for vulnerable programs can be found here:
    
    How to detect vulnerable and out-dated programs using Secunia Personal Software Inspector
    

Your computer should now be free of the Antivirus .NET program. You may want to consider purchasing the PRO version of Malwarebytes Anti-Malware to protect against these types of threats in the future, as if you had the real-time protection component, that comes with the paid for version, activated it would not have allowed this infection to install.

If you are still having problems with your computer after completing these instructions, then please follow the steps outlined in the topic linked below:

Preparation Guide For Use Before Using Malware Removal Tools and Requesting Help

 

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Associated Antivirus .NET Files:

%Temp%\<random>\<random>.exe

File Location Notes:

%Temp% refers to the Windows Temp folder. By default, this is C:\Windows\Temp for Windows 95/98/ME, C:\DOCUMENTS AND SETTINGS\<Current User>\LOCAL SETTINGS\Temp for Windows 2000/XP, and C:\Users\<Current User>\AppData\Local\Temp in Windows Vista, Windows 7, and Windows 8.

 

Associated Antivirus .NET Windows Registry Information:

HKEY_CURRENT_USER\Software\<random>
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\PhishingFilter "Enabled" = '0'
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings "ProxyOverride" = '<local>'
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings "ProxyServer" = 'http=127.0.0.1:8992'
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings "ProxyEnable" = '1'

 

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BleepingComputer.com can not be held responsible for problems that may occur by using this information. If you would like help with any of these fixes, you can ask for malware removal assistance in our Virus, Trojan, Spyware, and Malware Removal Logs forum.

If you have any questions about this self-help guide then please post those questions in our Am I infected? What do I do? and someone will help you.