Why is the option to preview PDF documents in ArcGIS Hub unavailable?

Answer

As of the ArcGIS Online February 2024 release, the option to preview PDF documents is no longer available and is a known limitation. These documents do not have a URL for preview. To review the documents, they must be downloaded by clicking the Download button in ArcGIS Hub. In a scenario where a PDF file with malicious JavaScript code is hosted on ArcGIS Online and a user unknowingly opens the file while logged into the browser, the browser's cross-domain restrictions are rendered ineffective.

Malicious JavaScript codes are challenging to detect as the code uses obfuscation methods, such as logical operation, string segmentation, and string compression. This exposes users to risks of virtual attacks such as stored cross-site scripting (XSS). While there are existing browser plugins to block JavaScript, the risk remains as there may be browsers without the plugins. Hence, to maintain security at its best, the preview for PDF documents is now unavailable in ArcGIS Hub.