Yontoo Adware - what it is, signs to watch for, and how to remove it

Yontoo

What it is

Yontoo is adware for Windows and Mac that comes as “helpful” web apps or browser add-ons (like downloaders or video helpers). Once installed, it can hijack your browser (change search/homepage), track what you do online, and flood pages with shady ads. Background and cleanup notes: https://gridinsoft.com/threats/yontoo

Why it matters

Extra ads and tracking slow your browser, hurt privacy, and can lead to more risky downloads or fake updates.

How it works 

  • Bundle: rides along with free installers or “video downloader” extensions.

  • Hijack: swaps your search/homepage and injects ads into pages.

  • Track: logs sites you visit and clicks for ad targeting.

  • Persist: adds startup tasks or re-installs via helper apps.

Red flags

  • Search engine or homepage changes on its own.

  • New toolbar/extension appears after installing an unrelated app.

  • More pop-ups and “recommended” links than usual.

  • Browser feels slow; unknown processes run at startup.

Do it right

  • Remove suspicious extensions from all browsers; uninstall unknown apps.

  • Reset browser settings; clear cache and site data.

  • Run a full scan with reputable anti-malware.

  • Reinstall only from official stores/vendor sites; skip “optional offers.”

  • Keep the OS, browsers, and security tools updated.

    Threat Glossary (A–Z)

    All A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

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