I'm just trying to ignore the least likely.
1/. avast! does not delete by default.
In both cases
2/. I downloaded from the link supplied by timarose (reasonable assumption made that he/she actually installed file from the source quoted rather than from some other site not mentioned).
3/. Jotti and Virustotal found nothing
4/. avast!, Bitdefender & Threatfire found nothing to object to on test PC.
5/. Programs installed and remain on test PC (Spystopper is annoying but so far it's still there).