If you mean enhanced shopping assistant it is malware you picked up.
I could post a link to a site that provides removal instructions but eBay Board Rules no longer permit posting links to sites outside of eBay.
Just do a "Google Search" for "enhanced shopping assistant removal" and you will get the information your require.
If you need further assistance I would suggest posting on the
eBay Computers Discussion Board
http://community.ebay.com/t5/Computers-Networking-I-T/bd-p/212