Milo,
(a) "Adobe PDFs" is not correct terminology. The PDF standard was standardised back in 2008 by Adobe under ISO ISO 32000-1.
(b)
"the best answer is to ditch the Adobe Reader and instead use an alternative such as the Foxit reader"
Utter tosh.
PDF problems are not necessarily related to a specific reader.
See
this article.... and specifically I draw your attention to the Foxit vulnerability mentioned.
The
BEST answer is to keep your guard up, and remain weary of attachments that you are not expecting, even from what you might perceive to be a trustworthy originator. As are the usual old adages making sure you do your day-to-day computing logged in as an unprivileged user, running up to date AV etc. etc.