With the retirement of IE11, Microsoft introduced "IE Mode" within the Chromium-based Microsoft Edge browser.

In the legacy IE11 model, the ActiveX control often ran with the same privileges as the user or the browser process itself. Unlike modern browsers that utilize "sandboxing" to isolate web content from the operating system, the Adobe plugin in IE11 had deep system integration. While this allowed for robust features—such as digital signatures, complex form filling, and 3D PDF viewing—it also created a direct attack vector for malicious PDFs to compromise the host system.

Adobe Reader Plugin Internet Explorer 11 _verified_ File

With the retirement of IE11, Microsoft introduced "IE Mode" within the Chromium-based Microsoft Edge browser.

In the legacy IE11 model, the ActiveX control often ran with the same privileges as the user or the browser process itself. Unlike modern browsers that utilize "sandboxing" to isolate web content from the operating system, the Adobe plugin in IE11 had deep system integration. While this allowed for robust features—such as digital signatures, complex form filling, and 3D PDF viewing—it also created a direct attack vector for malicious PDFs to compromise the host system.