Hi , when I go to : http://portableapps.com/apps/office/libreoffice_portable and download 4.2.1 file for Windows 123MB I go this (see attachement)
I scan the URL with Virustotal : nothing found :
https://www.virustotal.com/fr/url/1d33ed02aa74cc594625c458a07cc69950f64218b7ba624a411ee9af4cb47ceb/analysis/1393236606/
I disable Avast for 10 mn, download the file “LibreOfficePortable_4.2.1_MultilingualNormal.paf.exe” and scan it with Avast : no virus found
Win32:Evo-gen [susp] = suspicious
send file to avast lab, using one of these options
You can upload files and report issues to avast here : http://www.avast.com/contact-form.php (select subject according to Your case)
You can use mail
send to virus@avast.com in a password protected zip file
mail subject: False Positive / undetected sample (select subject according to your case)
zip password: infected
or you can send files from avast chest
how to use the chest. http://www.avast.com/faq.php?article=AVKB21