ExtenBro is a DNS changing Trojan that blocks users from accessing security sites in order to prevent them from downloading antivirus software. When installed, a scheduled task will be created that automatically launches the Trojan on startup.
Once started, ExtenBro will change a computer’s DNS settings to use the following DNS servers:
When a computer is set to these DNS servers, they will no longer be able to connect to sites associated with well known security software. In BleepingComputer’s tests, this includes the following domains:
When attempting to connect to these sites, the browser will display an error similar to the following message:
This site can’t be reached www.malwarebytes.com’s server IP address could not be found.
Try running Windows Network Diagnostics.
This Trojan will also add a root certificate to the Windows certificate store. This allows it to monitor encrypted traffic while a infected user browses the web.
More information about ExtenBro can be found here.
How was ExtenBro installed on my Computer?
It is important to note that ExtenBro is typically bundled with and installed by free programs that did not adequately disclose that other software would be installed along with it. Therefore, it is important that you pay close attention to license agreements and installation screens when installing anything off of the Internet. If an installation screen offers youÂ CustomÂ orÂ AdvancedÂ installation options, it is a good idea to select these as they will typically disclose what other 3rd party software will also be installed. Furthermore, If the license agreement or installation screens state that they are going to install a toolbar or other unwanted adware, it is advised that you immediately cancel the install and not use the free software.
If you are not sure how ExtenBro was installed on your computer, then it most likely was installed via an adware bundle. As this program is installed without your permission, blocks you from reaching sites, and installs a root certificate, you should remove it. To remove ExtenBro you can use the removal guide below to remove it for free.
MBAM will now start and you will be at the main screen as shown below.
We now need to enable rootkit scanning to detect the largest amount of malware and unwanted programs that is possible with MalwareBytes. To do this, click on the Settings button on the left side of the screen and you will be brought to the general settings section.
Now click on the Protection tab at the top of the screen. You will now be shown the settings MalwareBytes will use when scanning your computer.
At this screen, please enable the Scan for rootkits setting by clicking on the toggle switch so it turns green.
When MBAM is finished scanning it will display a screen that displays any malware, adware, or potentially unwanted programs that it has detected. Please note that the items found may be different than what is shown in the image below due to the guide being updated for newer versions of MBAM.
You should now click on the Remove Selected button to remove all the selected items. 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.
When Zemana has finished finished scanning it will display a screen that displays any programs that have been detected. Please note that the items found may be different than what is shown in the image below.
Review the scan results and when you are ready to continue with the cleanup process, click on the Next button to delete or repair all of the the selected results. Once you click on the Next button, Zemana will remove any unwanted files and fix any modified legitimate files. If you receive a warning that Zemana needs to close your open browsers, please close any web browsers that may be open and then click on the OK button to continue.
Zemana will now create a System Restore Point and remove the detected files and repair any files that were modified.
HitmanPro will now begin to scan your computer for infections, adware, and potentially unwanted programs. When it has finished it will display a list of all the items that Hitman has found as shown in the image below. Please note that the items found may be different than what is shown in the image.
You should now click on the Next button to have HitmanPro remove the detected items. When it is done you will be shown a Removal Results screen that shows the status of the various programs that were removed. At this screen you should click on the Next button and then if prompted you should click on the Reboot button. If HitmanPro does not prompt you to reboot, please just click on the Close button.
Once your computer has has restarted or you pressed the Close button, you should now be at your Windows desktop.
Your computer should now be free of the ExtenBro DNS Changing Trojan program. If your current security solution allowed this program on your computer, you may want to consider purchasing the full-featured version of Malwarebytes Anti-Malware to protect against these types of threats in the future.
If you are still having problems with your computer after completing these instructions, then please follow the steps outlined in the topic linked below:
Are Your Protected?
While Malwarebytes Anti-Malware, Zemana AntiMalware & HitmanPro will scan and clean a computer for free, the free versions do not offer real-time protection. If you want to be fully protected at all times then it is recommended that you purchase a premium version.
Purchase the full-featured version of Malwarebytes Anti-Malware, which includes real-time protection, scheduled scanning, and website filtering, to protect yourself against these types of threats in the future!
Purchase the full-featured version of Zemana AntiMalware, which includes second opinion malware scanner when other solutions do not work, cloud scanning, and super-fast scan time, to protect yourself against these types of threats in the future!
Disclaimer: While we do earn a commission from the sale of the above products, rest assured we only recommend them due to their effectiveness.