Acrobat Reader does let you sign PDFs and fill in forms, those were the two use cases you mentioned. Windows has a built-in PDF reader with basic editing funct

Acrobat Reader does let you sign PDFs and fill in forms, those were the two use cases you mentioned. Windows has a built-in PDF reader with basic editing functionality in the form of Microsoft Edge actually (although I've never used it for that purpose to be honest). As for a non-malware PDF editor, I'm not sure if Preview.app is such a great example in light of the recent image processing zero-days ;)