Question about PDF exploits

How does malware use PDF exploits to download itself? The only way i can think of is using a email with the malware attached that will attempt to recon the system and find a installed vulnerable PDF reader and trigger it’s infection routine. A example let’s say you get a email that has a PDF attached you open the email with a vulnerable PDF reader and the malware downloads on your system how exactly does this work? What i want from a answer is what exactly this attack is how it works how someone would do it and how/why is it used in malware along with any real life examples these examples could be malware from the past or present making use of this type of attack to vulnerabilities in common PDF readers that have had recent vulnerabilities come to light or even attached links to open source exploits Note: This question is not the same as the one linked because i was not asking if a PDF could contain malware i was looking for how that PDF can contain malware and how it works and what ways a attacker could pull this off along with any vulnerabilities that could be used and any source code that could serve as a example or any past or present malware using said methods