Microsoft Temporarily Disables MSIX App Installers to Prevent Malware Abuse
Feb 08, 2022
Microsoft last week announced that it's temporarily disabling the MSIX ms-appinstaller protocol handler in Windows following evidence that a security vulnerability in the installer component was exploited by threat actors to deliver malware such as Emotet, TrickBot, and Bazaloader. MSIX , based on a combination of .msi, .appx, App-V and ClickOnce installation technologies, is a universal Windows app package format that allows developers to distribute their applications for the desktop operating system and other platforms . ms-appinstaller, specifically, is designed to help users install a Windows app by simply clicking a link on a website. But a spoofing vulnerability uncovered in Windows App Installer ( CVE-2021-43890 , CVSS score: 7.1) meant that it could be tricked into installing a rogue app that was never intended to be installed by the user via a malicious attachment used in phishing campaigns. Although Microsoft released initial patches to address this fla...
