Introduction Computer security deals with techniques engaged to maintain security within a computer system.(Gollmann,2011)Computer security has been prevalent since the early ages of computers due to the inherent risks accompanied by skilled interventions by hackers since the invention of and throughout the internet.Computer security has been around for 40 years and counting.(Gollmann,2011)Computer security involves both network and information security.Information security is a kind of security which addresses the protection of all receiving and delivering communication data, technologies, as well as media content.While network security addresses the concerns required to protect components, objects or regions/areas.Computer security is not only a science but also an art. It is an art due to the fact that no system can be considered secure without an examination of of how it is to be utilised.(Bishop,2003)According to (Carroll,1987), there is no such thing as computer security; there are only varying degrees of insecurity. Computer security is easier to break than it is to build a fully secure computer.(Salomon,2006)MalwareMalware, also known as Malicious Software, is inclusive of computer viruses, worms, as well as trojan horses. Spyware and dishonest adware also contribute to Malicious Software. Malicious logic thwarts many mechanisms despite our best efforts(Bishop,2003)Malicious software,also known as Malware, has been prevalent since computers have been invented. With the constant evolution of malicious software and attack tools, today’s malware have a far greater impact now as compared to the attacks of the past.(Skoudis,2004) Malware is used to overpower the processing abilities of online systems or to acquire access to protected systems by concealed means. Malware is inclusive of viruses which segmentate themselves. A computer virus passes from computer to computer just like a biological virus passes from person to person.(Newman,2010) Malware also includes computer Worms, which are able to clone themselves until usable resources such as memory space and hard drive space are ultimately filled up.Trojan horses are malware camouflaged as useful, inviting and/or important pieces of software.Other types of Malware such as concealed software applications, spyware, adware and bots have been designed to run and execute much to the oblivion of the user.Spyware tends to covertly go around collecting information of users and then store records of the information.Information such as activities during web surfing may be taken advantage of and abused during a social engineering attack.Polymorphic threats tend to gradually develop to escape being detected.Virus and worm hoaxes are malware which do not exist in which employees spend time raising awareness about.Polymorphism is a type of malware which constantly switches its detectable attributes,So as to evade being detected.Polymorphism is utilised to avoid pattern-matching detection used by security solutions, such as antivirus software.(Lord,2017)Back door is a form of malware which acquires access to systems or networks through newly identified access methods. Denial-of-Service(DoS) attacks are attacks in which the hacker relays a huge number of information or connection requests to the targeted system. The system being targeted begins to get overwhelmed and is in turn unable to respond to genuine service requests.The outcome of this results in the targeted system crashing and leaves the system incapable of executing day to day functions.Distributed denial-of-service (DDoS) is a kind of software attack in which a synchronized request stream is projected against the targeted system, from various locations, all at the same time.The term ‘Botnet’ was derived from the two words ‘robot’ and ‘network’, in which cybercriminals utilise exceptional Trojan viruses to breach the security of several users’ computers.(“What is a Botnet? – Definition,”n.d.)A botnet is an army of compromised computers that take orders from a botherder, in which a botherder, also known as an immoral hacker, which utilises the botnet for financial gain and or to utilise as a weapon against others.(Schiller et al., 2007)Many botnets successfully avoid being detected by IRC protocol based detection by switching to HTTP based command and control.(Qing, Mitchell & Wang,2009)Breached PasswordsPassword choices are a crucial issue for security. Because the password security of any system is very important, encryption algorithms and hash values are utilised to secure these systems.(Basta, Basta & Brown,2013) In order to prevent a password’s security from being breached as well as lower the probabilities of the hacker’s guessing strategies, it is vital to ensure that passwords chosen by users are able to thwart the hacker’s guessing strategies.Exhaustive searching also known as brute force, is to try all possible permutations of a certain length, using valid symbols.Other kinds of password guessing strategies include intelligent search, by using a limited namespace, and attempt passwords that are somewhat related with the user’s name, family, or other relatives’ or friends’ names or phone numbers or birth dates, or also attempting trendy and/or favoured passwords.Dictionary attacks are another form of password guessing in which the attacker attempts all possible passwords from a dictionary.Shoulder surfing can be classified into two different categories; weak shoulder surfing and strong shoulder surfing.A weak shoulder surfing attack completely depends on the attacker’s cognitive abilities to memorise the password entered by the user.(Ray,Gaur,Conti,Sanghi & Kamakoti,2016)In strong shoulder surfing attacks, the attacker utilises external devices like miniature cameras or video mobile phones to record the entire session and can subsequently log in with observed credentials.(Ray et al.,2016)Keyloggers can do no harm in terms of a system’s stability. However, for end-users, keyloggers are extremely dangerous as an intruder can utilise them to eavesdrop on passwords or confidential information entered by the end-user. (Zaytsev,2007)The usage of keyloggers is detrimental to end-users due to the end-users lack of knowledge about the concealed keylogger working behind the end-users’ backs.The keylogger is capable of recording and storing all sorts of confidential and private credentials of the end-users utilising the infected system(s).Keyloggers are a type of malicious software in which end-users may suffer from identity theft in which the attackers steal the end-users credentials as well as information and pass off the stolen information as their own. All in all, computer security is essential in order to defend our computer systems and ensure our important as well as confidential data that are being transmitted are secure.By using preventive measures when choosing our passwords and not sharing them anywhere where it is possible for hackers to discover easily, we are essentially protecting ourselves from potential attacks. By installing applications for filtering and preventing malware infiltration for security measure, even though they are not 100% secure, we lessen the risk of being attacked by viruses and other malware.