Though i know that avast is NOT open source and is COPYRIGHTED, still i would like to seek permission to advertise avast to express my gratitude to THE AVAST TEAM that it has removed 20 viruses, 40 Trojans, 1 ad-ware from my computer.
Well, I don’t know what exactly you mean, but you are certainly welcome to spread the word 
If you want some logos, for example, they are here:
http://avast.com/eng/logos.html
Thanks for logos.