just wanted to get your thoughts on this:
ClamAV finds a PUA called 'BlackRain' in this file:
As such, it isn't an issue with the launcher, and I guess it's not the dll compression either, seeing there's only one file affected.
For comparison, I've downloaded the 'regular' LibreOffice and installed it, and ClamAV doesn't find anything there. Also the old OpenOfficePortable 3.1.1 that I'm using has a file of the same name, but without malware alert.
Quick search hints that 'BlackRain' has to do with some iOS jailbreak software. Any chance the packager has an iPhone and got himself some malware playing with it?