Like I learned on my skin, hardware acceleration and disk allocation/reclaim free space/corruption is sometimes a big problem with VirtualBox, that's the reason I switch to setup that I'm using right now. BTW VirtualBox is awesome.
I'm not running a straight version of VB (the joys of open source, at least with their main application, their guest additions are not open source, to my knowledge)
True - if you do not configure stuff from start like firewall, and in
Windows just
Windows Firewall & Defender is enough. Hot folders are not on
Windows machine but on Mac, so
Windows software (RIP) pick up stuff from them (TIFF, PDF, JPEG... etc)
If it is a means to go from host to guest and vice versa, it is a means to get things in to the
Windows machine. I can't remember how Parrallels does it, but in VB, the shared folders (this is what I'm thinking you are calling "hot folders", although for RIPS it's specifically called "hot folder") actually show up as networked drives within the
Windows VM. Those files that you mentioned could be used to execute malicious code as well. Not much of a worry if it's your own stuff, but if it's from 3rd parties, that's where the chance is. There was actually a case were PDFs viewed in web browsers spreading malware to all the OSs (Linux,
Windows and Mac) back in the summer of 2015 or 2016, something like that. Now that's using web browsers, but just to show it's possible to execute malicious code in those systems using those file types, something that all of the OSs can use.
I prefer hardware firewall to software and I don't necessarily trust
Windows in this area as well, because they have a history of skimping on hard security features for the convenience of the user (9x series anyone).