Defo 是一隻感染開機磁區的破壞性病毒。感染的方式是使用中毒的磁片開機。病毒會將自己的程式載入記憶體內。一旦常駐,就會感染任何存取過而沒有防寫保護的磁碟片。除了感染之外,該病毒還有一樣破壞性症狀,在 2月 27 日發作。發作時,該病毒會在攪亂中毒的硬碟資料後,出現一道問題,如果答對了,弄亂的資料會被還原回來,此時如果關機的話,硬碟就毀了。底下是出現的訊息 (正確答案是 4, 4, 2): WAIT for 1 MINUTES, please... Ok, If you give the right answer to the following questions, I will save your HD: A. Who has sung the song called "I'll be there"? 1. Mariah Care 2. The Escape Club 3. The Jackson Five 4. All (1-4) B. What is Phil Collins? 1. A singer 2. A drummer 3. A producer 4. Above all (1-4) C. Who has the MOST TOP 10 singles in 1980's? 1. Micahel Jackson 2.Phil Collins (featuring Genesis) 3. Madonna 4. Whitney Houston (1-4) CONGRATULATIONS!!! YOU successfully pass the quiz! AND NOW RECOVERING YOUR HARDISK.....