With　the　rapid　development　of　the　Internet　and　information　technology,　attacks　over　the　years　have　become　both　increasingly　numerous　and　sophisticated.　In　order　to　understanding　and　defending　against　cyber　attacks,　it　is　necessary　to　understand　the　classes　of　attack.　In　this　paper,　we　focuse　on　computer　and　network　attacks　and　survey　a　taxonomy　of　them.　©　2012　IEEE.