計算機病毒的介紹
計算機病毒具有傳播性、隱蔽性、感染性、潛伏性、可激發性、表現性或破壞性。接下來小編爲大家整理了計算機病毒的介紹，希望對你有幫助哦!
The computer virus is an outcome of the computer overgrowth in the 1980s. The cause of the term "computer virus" is the likeness between the biological virus and the evil program infected with computers. The origin of this term came from an American science fiction“The Adolescence of P-1”written by Thomas J. Ryan, published in 1977. Human viruses invade a living cell and turn it into a factory for manufacturing viruses. However, computer virusesare small programs. They replicate by attaching a copy of themselves to another program.
Once attached to me host Program, the viruses then look for other programs to "infect". In this way, he virus can spread quickly throughout a hard disk or an entire organization when it infects a LAN or a multi-user system. At some point, determined by how the virus was programmed the virus attacks. The timing of the attack can be linked to a number of situations, including a certain time or date, the presence of a particular file, the security privilege level of the user, and the number of times a file is used. Likewise, the mode of attack varies. So-called "benign" viruses might simply display a message, like the one that infected IBM's main computer system last Christmas with a season's greeting. Malignant viruses are designed to damage the system. The attack is to wipe out data, to delete flies, or to format the hard disk.
What Kind of Viruses Are There? There are four main types of viruses: shell, intrusive, operating system and source ode. Shell viruses wrap themselves around a host program and don't modify the original program. Shell programs are easy to write, which is why about half of viruses are of this type. Intrusive viruses Invade an existing program and actually insert a portion of themselves into the host program. Intrusive viruses are hard to write and very difficult to remove without damaging the host file.
計算機病毒是八十年代計算機飛速發展帶來的結果，計算機病毒這一名詞起因於在計算機上傳染的有害程序與生物學中病毒的相似性，該名詞起源於1977年出版的、由 Thomas J. Ryan寫的一本美國科幻小說《p-1的青春》。人體病毒入侵活的細胞後，就把它轉變成製造病毒的工廠。而計算機病毒是一些小程序，它們把自己的一個副本附加到另一個程序上面進行復制。
病毒程序一旦附加到一個主程序上，就開始尋找其他可以進行“感染”的程序。這樣，病毒就很快地佈滿整個硬盤，如果病毒感染了一個局域網或者一個多用戶系統，那麼就在整個組織內進行擴散。只有在某個點上病毒程序纔會發作(這是由病毒程序的設計所決定的)。攻擊的時間與多種情況有關，包括：某個時間或日期、特定用戶識別符的出現、用戶的安全保密等級和一個文件使用的次數。同樣，攻擊的方式也是各種各樣的。所謂的“良性”病毒可能只是簡單地顯示一個消息，如在去年聖誕節時，受感染的IBM公司的主要計算機系統顯示節日問候。惡性病毒被設計出來破壞系統。常見的攻擊方式是消除數據、刪除文件或者格式化硬盤。
