Hi, I'm the author of the post. I've been using JDownloader on Linux for years and never noticed a problem with Adware. Can you please elaborate? I'd really like to know more.
It seems to occur only using the web-installer, which is the one you're offically prompted at by the creators of JDownloader.
Well, I removed JDownloader and manually fixed the start page and search engines of firefox to remove the sweet-page stuff, but somehow my firefox is still screwed.
Questionable decision by the maker of JDownloader. I can't imagine that the money he gets for this is worth the damaged reputation.
Edit: I just ran an adware scanner. Besides the Sweet Page stuff, WindowsManagerProtect and Hold Page was installed. Several Registry Entries and Firefox setting were infected. Unbelievable ...