My AVG antivirus scan found this (among 11 others) file & wants to quarantine the file. Can I delete this file without an issue? Aren't "PUP" files just adware files?
"MacOS:InstallCore" is definitely a type of adware "infection." I suggest that you, as a minimum, allow AVG to quarantine this file and if no ill effects come about doing so, you can delete it later.
It also found files with name of Dragon Blaze, I googled that & it seems to be some game, I do not play those kind of role playing games, not sure how it ended up on my computer.
It used to be that you had to actively "participate" in getting something like this downloaded to your computer, but nefarious folks are much more cunning now and simply opening a web site can cause them to download (& potentially install). However, the newer versions of macOS makes it much more difficult for them to be successful at it.
Macs, to date, still do not get computer viruses, but they can be "infected" with malware & adware. FWIW, I use both EtreCheck and Malwarebytes for Mac to check for these types of things and avoid using a dedicated (meaning the app runs in background) anti-virus apps.
You may find the following articles helpful, as well: