【正文】 Securing Information Systems 169。 2022 by Prentice Hall Malicious Software: Viruses, Worms, Trojan Horses, and Spyware ? Malware (cont.) ? Spyware（間諜軟件） ? Small programs install themselves surreptitiously on puters to monitor user Web surfing activity and serve up advertising ? Key loggers ? Record every keystroke on puter to steal serial numbers, passwords, launch Inter attacks System Vulnerability and Abuse Essentials of Business Information Systems Chapter 7 Securing Information Systems 169。 2022 by Prentice Hall System Vulnerability and Abuse Essentials of Business Information Systems Chapter 7 Securing Information Systems Malware is active throughout the globe. These three charts show the regional distribution of worms and puter viruses worldwide reported by Trend Micro over periods of 24 hours, 7 days, and 30 days. The virus count represents the number of infected files and the percentage shows the relative prevalence in each region pared to worldwide statistics for each measuring period. 169。 2022 by Prentice Hall Hackers and Computer Crime System Vulnerability and Abuse Essentials of Business Information Systems Chapter 7 Securing Information Systems ? Hackers (黑客） vs. crackers（駭客） ? Activities include ? System intrusion ? System damage ? Cybervandalism ? Intentional disruption, defacement, destruction of Web site or corporate information system 169。 2022 by Prentice Hall 黑客一詞，原指熱心于計(jì)算機(jī)技術(shù)，水平高超的電腦專家，尤其是程序設(shè)計(jì)人員。但到了今天，黑客一詞已被用于泛指那些專門利用電腦搞破壞或惡作劇的家伙。對(duì)這些人的正確英文叫法是 Cracker，翻譯成“駭客”。駭客是“ cracker”的音譯，就是“破壞者”的意思。這些人做的事情更多的是破解商業(yè)軟件、惡意入侵別人的網(wǎng)站并造成損失。 169。 2022 by Prentice Hall Hackers and Computer Crime System Vulnerability and Abuse Essentials of Business Information Systems Chapter 7 Securing Information Systems ? Spoofing ? Misrepresenting oneself by using fake addresses or masquerading as someone else ? Redirecting Web link to address different from intended one, with site masquerading as intended destination ? Sniffer （嗅探器） ? Eavesdropping program that monitors information traveling over work ? Enables hackers to steal proprietary information such as , pany files, etc. 169。 2022 by Prentice Hall Hackers and Computer Crime System Vulnerability and Abuse Essentials of Business Information Systems Chapter 7 Securing Information Systems ? Denialofservice attacks (DoS) ? Flooding server with thousands of false requests to crash the work. ? Distributed denialofservice attacks (DDoS) ? Use of numerous puters to launch a DoS ? Bots ? Networks of “zombie” PCs infiltrated by bot malware 169。 2022 by Prentice Hall Hackers and Computer Crime System Vulnerability and Abuse Essentials of Business Information Systems Chapter 7 Securing Information Systems ? Computer crime ? Defined as “any violations of criminal law that involve a knowledge of puter technology for their perpetration, investigation, or prosecution” ? Computer may be target of crime, .: ? Breaching confidentiality of protected puterized data ? Accessing a puter system without authority ? Computer may be instrument of crime, .: ? Theft of trade secrets ? Using for threats or harassment 169。 2022 by Prentice Hall Hackers and Computer Crime System Vulnerability and Abuse Essentials of Business Information Systems Chapter 7 Securing Information Systems ? Identity theft ? Theft of personal Information (social security id, driver’s license or credit card numbers) to impersonate someone else ? Phishing（網(wǎng)絡(luò)釣魚） ? Setting up fake Web sites or sending messages that look like legitimate businesses to ask users for confidential personal data. ? Evil twins ? Wireless works that pretend to offer trustworthy WiFi connections to the Inter 169。 2022 by Prentice Hall 網(wǎng)絡(luò)釣魚是一種常見的網(wǎng)絡(luò)攻擊或詐騙手法。網(wǎng)絡(luò)詐騙分子通常是通過大量發(fā)送聲稱來(lái)自于銀行或其他知名機(jī)構(gòu)的欺騙性垃圾郵件，意圖引誘收信人給出敏感信息（如用戶名、口令、賬號(hào) ID 、銀行卡或信用卡詳細(xì)信息等）。最典型的網(wǎng)絡(luò)釣魚攻擊將收信人引誘到一個(gè)通過精心設(shè)計(jì)與目標(biāo)組織的網(wǎng)站非常相似的釣魚網(wǎng)站上，并獲取收信人在此網(wǎng)站上輸入的個(gè)人敏感信息。 169。 2022 by Prentice Hall Hackers and Computer Crime System Vulnerability and Abuse Essentials of Business Information Systems Chapter 7 Securing Information Systems ? Pharming（網(wǎng)絡(luò)嫁接） ? Redirects users to a bogus Web page, even when individual types correct Web page address into his or her browser ? Click fraud（點(diǎn)擊欺詐） ? Occurs when individual or puter program fraudulently clicks on online ad without any intention of learning more about the advertiser or making a purchase 169。 2022 by Prentice Hall Pharming借由入侵 DNS（ Domain Name Server）的方式，將使用者導(dǎo)引到偽造的網(wǎng)站上，因此又稱為 DNS下毒（ DNS Poisoning）。 DNS的功能是將網(wǎng)站的域名（如： 格式）轉(zhuǎn)換實(shí)際的 IP址（如： 格式），當(dāng)用戶在瀏覽器中請(qǐng)求訪問一個(gè)網(wǎng)站時(shí)，他會(huì)在其中輸入一個(gè)域名，這個(gè)域名請(qǐng)求首先會(huì)到達(dá)最近的一個(gè) DNS，將其解析為對(duì)應(yīng)的 IP地址，然后用戶才能得以連接上這個(gè)網(wǎng)站。所以一旦 DNS被入侵，網(wǎng)站域名與 IP地址的對(duì)照表遭到修改 ,這樣當(dāng)用戶在希望訪問一個(gè)正常網(wǎng)站時(shí)，就會(huì)在毫無(wú)知覺的情況下被引誘到釣魚網(wǎng)站或者一個(gè)含有惡意代碼的網(wǎng)站。 169。 2022 by Prentice Hall Worldwide Damage from Digital Attacks Figure 73 This chart shows estimates of the average worldwide damage from hacking, malware, and spam since 1998. These figures are based on data from mi2G and the authors. System Vulnerability and Abuse Essentials of Business Information Systems Chapter 7 Securing Information Systems 169。 2022 by Prentice Hall Internal Threats: Employees ? Security threats often originate inside an anization ? Inside knowledge ? Sloppy security procedures ? User lack of knowledge ? Social engineering: ? Tricking employees into revealing their passwords by pretending to be legitimate members of the pany in need of information System Vulnerability and Abuse