Not really sure how I ended up at this site …
http://igbandalarga.ig.com.br/
but while looking (since I can not read Portuguese) I saw an ad for Avast! and clicked on the link which took me here …
http://baixaki.ig.com.br/download/Avast-Home-Edition.htm 
All appears legitimate but a strange thing happened upon clicking the back button to go back to the first link above … the pictures, frames, etc started flashing on & off at a rapid rate. Also, the side scroll bar jumps up & down though the page does not … yet using the scroll wheel on my mouse scrolls the page up & down correctly. :o
Clicking the forward button to go to the Avast download page again takes me back to that page which formerly worked correctly and still does except that no picture show now. Clicking the back button / forward button several times produced the same results. :-\
Anyone have any idea about this? ???