OfferCore Virus


OfferCore is an application of the browser hijacker type that may affect the way your web browser functions. OfferCore is known for delivering sponsored search results and ads on the screen by replacing the main browser’s search engine and homepage.


The OfferCore virus can integrate with virtually all of the most popular browsers and hijack them

Browser hijackers aren’t the most pleasant type of software to deal with but they seem to find their way into our computers quite often. One of the latest variants of this software type is called OfferCore and, like a typical browser hijacker, it may replace the homepage of your browser and set a new search engine as the default search engine. In addition, during the time this hijacker is on your PC, you are likely to experience frequent page redirects and may also witness a stream of aggressive ads, banners, and pop-ups on every website you visit. OfferCore can integrate with virtually all of the most popular browsers, including Chrome, Firefox, Edge, Opera, etc., and hijack them. Unfortunately, you won’t be able to remove the browser changes and restore your browser’s settings to the state they were before the infection unless you fully uninstall the browser hijacker from the computer. That’s why we offer you a detailed removal guide to help you locate and safely uninstall OfferCore . We also offer you a professional removal tool that you can use to scan your computer for this and other undesirable software.

What does OfferCore seek to accomplish?

Just like any other browser hijacker, the purpose of OfferCore is to generate and display numerous online ads. For example, every time you start a new browsing session you may see various pop-ups, banners, promotional messages, and colorful notifications that constantly prompt you to click on something. Since you are on this page, the activities of this hijacker have probable become too intrusive to tolerate and you’ve realized that no matter what you do, you can’t stop them. The reason is that the creators of these ads are paying the developers of the browser hijacker to display them as much as possible. In fact, the advertisers pay the hijacker’s creators based on the number of clicks the ads collect from users. This is done according to remuneration models such as the infamous Pay-Per-Click, which is actually the main method that dictates the behavior of programs like OfferCore.

How OfferCore achieves its goal

In order to get more user clicks and to generate greater revenue for their developers, browser hijackers such as OfferCore tend to “hijack” the default browser by installing a new homepage that redirects to specific sponsored sites. They also tend to change the main search engine with another one, which typically generates sponsored results and pay-per-click ads. Sometimes, the browser hijackers may go even further by automatically redirecting your web searches to sites that are considered to match your interests and latest search queries.

Being exposed to random sites with aggressive web ads, however, is not only unpleasant but also may lead to an accidental encounter with security hazards, including Trojans, Ransomware, and other viruses.

This may seem quite disturbing to you, and there really is a reason to be concerned and to avoid the sponsored messages that OfferCore displays on your screen. Legitimate-looking ads can be used to distribute all sorts of computer infections and, as a matter of fact, a great number of Ransomware cryptoviruses use infected ads to contaminate the web users.

For this purpose, we would like to advise our readers to keep away from random pop-ups, banners or similar advertisements and to take the necessary measures to uninstall their source as there’s simply no need to risk the safety of their computers by accidentally clicking on something potentially misleading.


Name OfferCore
Type  Adware/Browser Hijacker
Detection Tool

anti-malware offerOFFER *Read more details in the first ad on this page, EULA, Privacy Policy, and full terms for Free Remover.

Remove OfferCore Virus

To try and remove OfferCore quickly you can try this:

  1. Go to your browser’s settings and select More Tools (or Add-ons, depending on your browser).
  2. Then click on the Extensions tab.
  3. Look for the OfferCore extension (as well as any other unfamiliar ones).
  4. Remove OfferCore by clicking on the Trash Bin icon next to its name.
  5. Confirm and get rid of OfferCore and any other suspicious items.

If this does not work as described please follow our more detailed OfferCore removal guide below.

If you have a Windows virus, continue with the guide below.

If you have a Mac virus, please use our How to remove Ads on Mac guide.

If you have an Android virus, please use our Android Malware Removal guide.

If you have an iPhone virus, please use our iPhone Virus Removal guide


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).



Press CTRL + SHIFT + ESC at the same time and go to the Processes Tab (the “Details” Tab on Win 8 and 10). Try to determine which processes are dangerous. 


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

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    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. 


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


    You are now in the Control Panel. Look for suspicious entries. Uninstall it/them.

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


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


    To remove parasite on your own, you may have to meddle with system files and registries. If you were to do this, you need to be extremely careful, because you may damage your system.

    If you want to avoid the risk, we recommend downloading SpyHunter
    a professional malware removal tool.

    More information on SpyHunter, steps to uninstallEULAThreat Assessment Criteria, and Privacy Policy.

    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.

    Open the start menu and search for Network Connections (On Windows 10 you just write it after clicking the Windows button), press enter.

    1. Right-click on the Network Adapter you are using —> Properties —> Internet Protocol Version 4 (ICP/IP), click  Properties.
    2. The DNS line should be set to Obtain DNS server automatically. If it is not, set it yourself.
    3. Click on Advanced —> the DNS tab. Remove everything here (if there is something) —> OK.



    • After you complete this step, the threat will be gone from your browsers. Finish the next step as well or it may reappear on a system reboot.

    Right click on the browser’s shortcut —> Properties.

    NOTE: We are showing Google Chrome, but you can do this for Firefox and IE (or Edge).


    Properties —–> Shortcut. In Target, remove everything after .exe.

    Browser Hijacker Removal Instructions

    ie9-10_512x512  Remove OfferCore from Internet Explorer:

    Open IE, click  IE GEAR —–> Manage Add-ons.

    pic 3

    Find the threat —> Disable. Go to IE GEAR —–> Internet Options —> change the URL to whatever you use (if hijacked) —> Apply.

    firefox-512 Remove OfferCore from Firefox:

    Open Firefoxclick  mozilla menu  ——-> Add-ons —-> Extensions.

    pic 6

    chrome-logo-transparent-backgroundRemove OfferCore from Chrome:

    Close Chrome. Navigate to:

     C:/Users/!!!!USER NAME!!!!/AppData/Local/Google/Chrome/User Data. There is a Folder called “Default” inside:

    Rename the Folder to Backup Default

    Rename it to Backup Default. Restart Chrome.


    Type Regedit in the windows search field and press Enter.

    Inside, press CTRL and F together and type the threat’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 doesn’t help, download the anti-virus program we recommended or try our free online virus scanner. Also, you can always ask us in the comments for help!


    About the author


    Brandon Skies

    Brandon is a researcher and content creator in the fields of cyber-security and virtual privacy. Years of experience enable him to provide readers with important information and adequate solutions for the latest software and malware problems.

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