Auto-enabling a bho in internet-explorer

Question

last week I downloaded an extension (i.e) for lyrics, and to my amazement it was automatically enabled without the prompt. As a programmer i'm interested to know how this is done, I already tried to change some reg keys - but with no success. the program can be found here ( but beware because i think it's malware) : bobylyrics.co. I already wasted days on this, and my OCD doesn't let me stop, so please help 8-)