Viruses prevalence on the Internet Have your computers recently been attacked by some viruses Internet The so-big worm (Aug 11, 2003) 星 The blaster worm Domain 2 Domain 1 The Slammer virus,...... a virus can affect the whole Internet in 30 seconds to minutes, if without any countermeasuresViruses prevalence on the Internet • Have your computers recently been attacked by some viruses? The So-big worm (Aug. 11, 2003), The Blaster worm , The Slammer virus,…… • A virus can affect the whole Internet in 30 seconds to minutes, if without any countermeasures