垃圾郵件之傳播與使用行為調查研究

Abstract

每日收到不請自來的垃圾郵件，已為網路社會的普遍現象，不僅影響工作效率，也危害電子郵件通訊安全。垃圾郵件議題涉及層面甚廣，需以多元觀點視之，過去研究多以過濾技術的研發、與各國法制之面向探討，較少以傳播與使用者觀點之相關研究。本研究目的在於探析垃圾郵件傳播過程中三個主體：垃圾郵件發送者(Spammer)、垃圾郵件(Spam Mail)、以及垃圾郵件接收者(Spam Receivers) 之不同特性。使用研究方法主要為內容分析法和網路問卷調查。基於傳播理論說明內容分析能作為特定傳播者及其傳播訊息分析的一種工具，取代以訪問人的方式進行研究，因此研究者蒐集數百份大量文件，舉凡刑警局偵九隊網路警察公告之案例、垃圾郵件過濾廠商提供之日誌檔、相關機構組織公布之研究報告、線上論壇和討論群文章等，以及針對一電子郵件帳號隨機抽樣1000封垃圾郵件等作為內容分析之研究標的。而為瞭解垃圾郵件接收者對於垃圾郵件反饋之態度與行為，進行網路問卷調查，共計回收2112份有效問卷，以SPSS 12.0統計軟體進行分析。

研究結果發現，垃圾郵件發送者多為學生及具有深度資訊背景人士，動機主要以獲利為目的，亦有其他基於滿足好奇心或想獲得成就感的特殊案例，其發送手法多以心理層面的偽裝、詐騙（如網路釣魚[Phishing]），與技術層面的躲避、綁架伺服器（如僵屍電腦[zombie]）等手段，發送的時間和對象也為達成更高回覆率而常有所特別設定；垃圾郵件常見類型為成人情色、金融理財、產品資訊，而資訊類型由純文字與HTML多媒體格式比率約佔各半，部分則含有輸入式表單或加附聯絡人資料等。大部分使用者皆有接收垃圾郵件的經驗，其中約有69.1％面臨嚴重垃圾郵件問題，然而卻有約58.8％會企圖打開符合興趣主題的垃圾郵件，而且未來仍不排斥接收此些郵件。垃圾郵件主要困擾使用者的原因是與正常郵件的混雜、以及含有具攻擊性的病毒，通常男性(13.0％）較女性(9.6％)對於垃圾郵件的容忍程度較高，但另一方面，男性在垃圾郵件防制工具的使用意願上較女性低(21.6% vs. 23.9%)。觀察使用者經常點選的垃圾郵件類別，發現往往也為平時常見的類別，由此發現，整個垃圾郵件傳播過程中，各個主體皆有相互影響的密切關係。未來研究可以探討以不同載具上網收發信件的使用者，面對垃圾郵件的態度與行為特性，以及可以朝向使用者如何保護個人電腦與電子郵件信箱安全的方向著手。Spam mail has been a growing problem on the Internet. It causes work inefficiency and damages people’s information security. Previous research on spam mail mostly focused on technical aspects like building spam filtering systems, or concerned with legal issues like initiating law enforcement. Communication or users’ aspects were less found in related studies. The main purpose of this study, therefore, is to explore various characteristics of the spam mail communication process. The process is consisted of three major components in this study, i.e., spammers (senders), spam mails (messages), and users (receivers). The study uses content analysis and online questionnaire methods. Over hundreds of related cases and a thousand of spam mail samples have been analyzed based on communication theory. As to the online questionnaire, there are 2112 effective questionnaires have been collected and analyzed by using SPSS v12.0.

The results show that spammers often have higher level of computer knowledge or skills, and many of them are students. Their intentions to send spam mails are various, and making profit is one of the most prominent motives, others like curiosity and sense of achievement have been also considered to be important. Spam tricks may include deception, dishonesty, camouflage, offensiveness, etc. They often select target users and send spam mails using specific time periods. As to the characteristics of spam mails, sexual, financial, and products rank the top three categories, but some of spam mails cannot be classified, such as “detection-investigation” and “dog training”, etc. Both plain text and HTML formats were used in spam mails. Most of the users in this study have received spam mail, and more than 69.1% feel irritating to receive spam mails. However, there are 58.8% of users would still like to open spam mails if the topics were interesting, and are not against in receiving such mails in the future. Interestingly, the top three subject categories of users’ choice of clicking spam mails are coincident with the results of spam mails analysis. Major problems in receiving spam mails include mixing up with normal mails and greater probability of getting virus attack. Male users (13.0%) have higher tolerance in receiving spam mails than female users (9.6%), but use less skills in managing spam mails than those of female users (21.6% vs. 23.9%). Based on the above results, it is worthwhile to investigate and improve spam mail literacy for the future studies.