Does Mac OS X 10.13.6 Quartz PDFContext make computer vulnerable to groups like Sednit?

With all the vulnerabilities revealed in users still employing OSX, I’m concerned about vulnerabilities that may still exist for Mac OS X 10.13.6 Quartz PDFContext in downloading pdf files for later viewing or using the print as pdf for websites where a pdf of a document or even communication (live chat) is necessary for legal and research purposes. I keep my MacPro OS High Sierra 10.13.6 updated for security patches regularly but I am concerned these may not address this issue. I am particularly concerned about Apple’s addressing Xagent, Xtunnel, Sedreco, and DownDelph.  According to eset “Dissection of  Sednit Espionage Group” all of these target Windows in particular and they discuss these the exploitation of that platform almost exclusively. Still they say Sednit is not far behind in developing the code to make inroads for Apple products claiming  iOS and OSX have already been compromised, though I am not certain Apple has already addressed these vulnerabilities (I’m assuming yes). Considering all these disturbing revelations,  must users of Mac OS X 10.13.6 Quartz PDFContext beware?

Thanks.