Security threatsSecurity threats defined by acts or objects that pose a danger to the security of a systemSecurity threats divided into 2 types Technical attacks and non-technical attacksTechnical attacksTechnical attacks considered as one of the most difficult problems that e-commerce should face. The perpetrators of these attacks usually target sites such as banks, credit card payment gateways. (McDowell, 2009) Denial of Service Attack The DoSDenial of Service attack occurs when a malicious user attempts to flood a networked computer or device with traffic in order to make the computer or device unavailable. The attack gets its name from its objective which it is meant to negate. the ability of an institution or company to provide a service to its users or customers. (University, 2013) According to the US Computer Emergency Preparedness Team, the symptoms of DoS are: (McDowell, 2009) Slow network performance Unavailability of a particular website Unable to access a website Distributed Denial of Service Attack DDoS attack occurs when the attacker gains access to as many computers as possible and uses these computers to send a stream of data packets to the target computer (Efraim Turban, 2006). An example of DDoSDDoS considered the biggest security fear for IT professionals, the most famous DDoS attacks occurred in February 2000 where websites such as Yahoo, Buy.com, E-bay, Amazon and CNN were attacked and left inaccessible for several hours (O'Raghallaigh, 2010). The MalwaresTechterms website defines malware as software programs designed to damage or perform other unwanted actions on a computer system (Anon., nd) There are many types of malware, including: Virus: a piece of software code that inserts into the target in order to propagate...... middle of paper...... Available at: http://www. techterms.com/definition/malwareAnon., and Trojan. [Online] Available at: http://www.techterms.com/definition/trojanhorseBill Wyman, WSHLS, 2013. Email Phishing Attacks, sl: The SANS Securing The Human program. Efraim Turban, DK. JKL,. DV, 2006. Electronic commerce: a managerial perspective. Prentice Hall ed. sl:snEngineering, MR t. S., 2005. Measuring resistance to social engineering. McDowell, M., 2009. Understanding Denial of Service Attacks. [Online]Available at: http://www.us-cert.gov/ncas/tips/ST04-015[Accessed December 2013].O'Raghallaigh, E., 2010. Major Security Issues in E-Commerce, sl: WebScience.University, H., 2013. What is a Denial of Service (DoS) attack?. [Online]Available at: http://huit.harvard.edu/faqs/what-denial-service-dos-attack[Accessed December 2013].