Do you mean this SplashLite? http://download.cnet.com/Splash-Lite/3000-13632_4-10972188.html?tag=mncol;1
If so it's an external download, meaning the software is not downloaded from Download.com but directly from the software developer at http://mirillis.com/en/
I've just downloaded that "installer" file myself and tested it with my own anti-virus, (ZoneAlarm), and also my anti-malware scanner Malwarebytes' Antimalware, and found no infection.
I also uploaded that installer file to Jotti's virusscan checker to test the file against a range of anti-virus scanners, and it also found none. Results here;
So it looks like the installer doesn't hold any viruses or other malware.
Can you remember what Avast found in those 3 errors? That might give a clue.
As to the volume icon I can't be sure, but are you sure the volme icon hasn't just hidden itself from that notification area tray? You could check this in Taskbar Properties, (right click the Taskbar and select Properties, then the "Customize" button.
If SplashLite keeps doing this though, then you may want to just uninstall it and try another media player. We often suggest the VLC Player in these forums.