As a follow up, I was feeling a tad guilty as I had started the thread. I went to the Palemoon website to check their FAQ and how to report problems.
The webpage for FAQ is
http://www.palemoon.org/faq.shtml#My...ware_complains. They mention there that some antivirus heuristics modes give false positives. Without knowing the exact Malware mentioned by Chris, it may be that simple.
BTW, I have absolutely no connection to Palemoon, just liked the program when I saw it and wanted to pass the word along.