TR/Zapchast.4 is a threat detected by either Microsoft Security Essentials, Windows Defender for Windows 8 or Microsoft Safety Scanner. This TR/Zapchast.4 threat is classified as PUP a Potentially Unwanted Program by Microsoft because it inflicts and acts as a malicious threat into your computer system. TR/Zapchast.4 is not a virus but it does act like one. TR/Zapchast.4 is adware which is bundled using custom installers and dropped on your computer during the installation process. Most users have no idea how this TR/Zapchast.4 threat is installed on there computer and what it is, until Microsoft Security Essentials, Windows Defender for Windows 8 or Microsoft Safety Scanner detects it as a malicious threat or virus. Follow our instruction to remove this TR/Zapchast.4 threat from your computer.