EXTMINOOP is classified as Win32:PUP-gen (potentially unwanted program).
What is PUP?
PUP is crapware. EXTMINOOP have several types of unwanted behaviour:

1. Displaying popup ads.
2. Hijacking your browser.
3. Infecting your desktop shortcuts, etc.
4. Inserting ads to the web pages.

EXTMINOOP can redirect your browser search, collect your personal information and sell it for advertising.
EXTMINOOP is usually hard in removing. Some people could not find uninstall program for EXTMINOOP in the Control Panel.
Sometimes EXTMINOOP uninstaller does not work.

How EXTMINOOP got on my computer?

Usually you got EXTMINOOP with as part of a bundle with another tool you downloaded from the Internet. Since EXTMINOOP manufacturer pays software developers for distributing EXTMINOOP within their applications, EXTMINOOP is often included as part of the installer.
Usually, you have not only one EXTMINOOP problem, but a bunch of similar WIN32:PUPs.

How to remove EXTMINOOP?

Step-by-step Guide for manual removal of EXTMINOOP:

1. Uninstall EXTMINOOP using Windows uninstallation applet (use Add/Remove Programs or Uninstall Program or Apps & features).
2. Open Task Manager to kill all "EXTMINOOP" related processes.
3. Use Windows search to find and remove "EXTMINOOP" files and folders.
4. Run services.msc to disable a "EXTMINOOP" Windows service.
5. Execute taskschd.msc to get rid of "EXTMINOOP" scheduled tasks.
6. Open regedit.exe and delete EXTMINOOP registry keys and values.
7. Check your shortcuts on your desktop and in the Start menu for EXTMINOOP presence. Fix infected shortcuts.
8. Remove a virus from Google Chrome.
9. Remove a virus from Internet Explorer.
10. Remove a virus from Mozilla Firefox.
11. Clean your Recycle bin and temporary files.