Internet Explorer pop under

[springe]

Hi. When I click on the internet explorer icon it just goes straight to an open pornographic web page. If i click on star for favourites it appears in the add box. How do I get rid of this its driving me mad. Ive deleted cookies and favourites. downloaded virus checker nothing is working. my children use my phone and do not want them to see this.Any ideas pls as tearing my hair out here. thank you