[bitsinthesky]

Unfortunately it seems pdfs linked there may also be malicious ( https://www.virustotal.com/gui/url/7e73cc3d685c77d88ad9cf769... ). I checked on some other pdf links ive downloaded previously and they were safe, so I don’t believe the software just flags everything.

But it could be if the coding book includes working examples and exercises, that would probably flag any system looking for code execution.

[scrlk]

I'm inclined to say that those are false positives, given the obscurity of the vendors who are flagging the URL.