Windows 8.1 with Comodo security. Attempt to install AOO 4.1 resulted in quarantine because of the trojan. The new install killed off AOO 4.0 so now I have no office apps available. Not good.
If you downloaded AOO from their official site (http://www.openoffice.org/), then it probably is just a false positive. Antivirus software are often too eager to mark stuff as viruses because they rely on inaccurate heuristics (in fact for Windows 8 I would suggest running only Windows Defender and certainly not paying for antivirus).
This is the Ask site for LibreOffice, though. Maybe you could try the latest LibreOffice version from http://www.libreoffice.org/ and see if it runs well? 