Remove Trojan Patched.AO and Fix DNSAPI.dll Missing Error

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This article is dedicated to helping users remove Trojan Patched.AO and fix the DNSAPI.dll missing  error, which may be connected to the trojan virus family, as users commonly refer to them. The DNSAPI.dll Missing Error can also be displayed on its own, but much of the time it is “broken” by the trojan in question.

WARNING!

Again, if you are here for the dnsapi.dll missing error, this may be related to a trojan virus called Win32/Patched.AO. The removal guide will provide solutions for both the error and the virus, if there is one.

Despite being predominantly called Viruses by most users, in reality Trojans are not, as surprising as this sounds. They are still very much malicious and dangerous, but the fine distinction between viruses and malware is that viruses can replicate and regenerate themselves even if you delete them. They have in-built capabilities to do so. Trojan Win32/Patched.AO and DNSAPI.dll Missing Error can not. Facts point that if you manage to remove them once, they will not come back to bother you again. That is why there is an entirely different classification called “malware” and this is the one the trojan belongs to.

dnsapi dll missing error

What is a Trojan?

The simplest explanation is the classical one. Just as the famous trojan horse it was named after, this type of malware serves as a front or back door, depending how you look at it. They basically get in and leak information to whoever created them, as well as serve as a weak point in the security system of your computer. If a Trojan is associated with another virus it can help that virus install itself on your machine without your authorization or knowledge. Hackers who create Trojans are often paid by hackers who make other viruses in order to use the network of infected computers to distribute their malicious work.

How does DNSAPI.dll Missing Error factor in the work of the Trojan?

The DNSAPI.dll file is a library file used by Windows in task related to internet access and for this reason it is often targeted by threats like Trojan Win32/Patched.AO. It is used by Window’s DNS Client API and if it has been tampered with or corrupted Windows cannot process the settings inside, thus causing a variety of DNS Client error files to pop up. A list of these errors include:

  • This application failed to start because DNSAPI.DLL was not found. Re-installing the application may fix this problem.
  • Dnsapi.dll not found.
  • The file Dnsapi.dll is missing.
  • Dnsapi.dll Access Violation.
  • Cannot register dnsapi.dll.
  • Cannot find C:WindowsSystem32\dnsapi.dll.

These errors will most often pop during start-up after a system power-on/reboot, but they can also appear when another program on your computer tries to access Dnsapi.dll. These errors are a sure sign you have a serious Trojan-related problem.

DO NOT try to simply replace Dnsapi.dll on your computer without dealing with the Trojan! It will remain installed on your compter and also there are many fake sites that offer manipulated .dll files. Even if the error disappears it could be because the .dll file is written more cleverly and Windows cannot recognize that the file is not the original one.

If you are seeing any of these errors on your computer then you must take adequate action against Trojan Win32/Patched.AO. The fact that Dnsapi.dll has been changed renders your computer vulnerable and also makes any firewall you have impotent in adequately dealing with attempts to install viruses on your computer. The more you wait the greater the chances you will have a bigger collection of other threats to deal with.

SUMMARY:

Name Patched.AO and DNSAPI.dll
Type Potentially Unwanted Programs and Files
Danger Level Medium.
Symptoms Unwanted Ads and Toolbars, search engine redirects.
Distribution Method Software bundles, Email attachments, online Ads, infected torrent files.
Detection Tool We generally recommend SpyHunter or a similar anti-malware program that is updated daily.

Remove Trojan Patched.AO and DNSAPI.dll

Step1

Some of the steps will likely require you to exit the page. Bookmark it for later reference.

Reboot in Safe Mode (use this guide if you don’t know how to do it).

Step2

This is the most important step. Do not skip it if you want to remove Trojan Patched.AO and DNSAPI.dll successfully!

Press CTRL + SHIFT + ESC at the same time and go to the Processes Tab. Try to determine which processes are dangerous. 

malware-start-taskbar

Right click on each of them and select Open File Location. Then scan the files with our free online virus scanner:

Drag and Drop Files Here to Scan
Maximum file size: 128MB.

This scanner is free and will always remain free for our website's users. You can find its full-page version at: https://howtoremove.guide/online-virus-scanner/




Scan Results


Virus Scanner Result
ClamAV
AVG AV
Maldet

After you open their folder, end the processes that are infected, then delete their folders. 

Note: If you are sure something is part of the infection – delete it, even if the scanner doesn’t flag it. No anti-virus program can detect all infections. 

Step3

Hold together the Start Key and R. Type appwiz.cpl –> OK.

appwiz

You are now in the Control Panel. Look for suspicious entries. Uninstall it/them. If you see a screen like this when you click Uninstall, choose NO:

virus-removal1

Step4

Type msconfig in the search field and hit enter. A window will pop-up:

msconfig_opt

Startup —> Uncheck entries that have “Unknown” as Manufacturer or otherwise look suspicious.

  • Remember this step – if you have reason to believe a bigger threat (like ransomware) is on your PC, check everything here.

Hold the Start Key and R –  copy + paste the following and click OK:

notepad %windir%/system32/Drivers/etc/hosts

A new file will open. If you are hacked, there will be a bunch of other IPs connected to you at the bottom. Look at the image below:

hosts_opt (1)

If there are suspicious IPs below “Localhost” – write to us in the comments.

Step5

WARNING!
To remove parasite, you may have to meddle with system files and registries. Making a mistake and deleting the wrong thing may damage your system.
Avoid this by using SpyHunter - a professional Parasite removal tool.

Keep in mind, SpyHunter’s malware & virus scanner is free. To remove the infection, you'll need to purchase its full version. More information about SpyHunter and steps to uninstall.

Type Regedit in the windows search field and press Enter.

Once inside, press CTRL and F together and type the virus’s Name. Right click and delete any entries you find with a similar name. If they don’t show up this way, go manually to these directories and delete/uninstall them:

  • HKEY_CURRENT_USER—-Software—–Random Directory. It could be any one of them – ask us if you can’t discern which ones are malicious.
    HKEY_CURRENT_USER—-Software—Microsoft—-Windows—CurrentVersion—Run– Random
    HKEY_CURRENT_USER—-Software—Microsoft—Internet Explorer—-Main—- Random

If the guide didn’t help you, download the anti-virus program we recommended or ask us in the comments for guidance!