Even with Widevine DRM, the decrypted frames eventually hit your RAM. Early extensions simply sniffed the network requests for *.mp4 or *.m3u8 (HLS playlist) files. Modern Udemy uses fragmented MP4s (fMP4) and tokenized URLs that expire every 15 minutes.
Enter the shadow economy of browser extensions: the . Specifically, the endless rabbit hole of “Chrome Zip File REPACKs.” You see them on sketchy forums, private Telegram channels, and GitHub repos that disappear faster than a Snapchat story. Udemy Downloader Extension Chrome Zip File REPACK
The urge to right-click, save-as, and hoard that DRM-protected MP4 is real. Even with Widevine DRM, the decrypted frames eventually