The purpose of this paper is to specifically focus on two types of malware: trojans and ransomware. To discuss what they are, how it works, method of spread, possible damage caused by them, common types of them and some famous examples, and also to show the ways to detect, prevent and recover from them.
Malware (a portmanteau for malicious software) is any software intentionally designed to cause disruption to a computer, server, client, or computer network, leak private information, gain unauthorized access to information or systems, deprive users access to information or which unknowingly interferes with the user’s computer security and privacy. By contrast, software that causes harm due to some deficiency is typically described as a software bug. Malware poses serious problems to individuals and businesses on the Internet. According to Symantec’s 2018 Internet Security Threat Report (ISTR), malware variants number has increased to 669,947,865 in 2017, which is twice as many malware variants as in 2016. Cybercrime, which includes malware attacks as well as other crimes committed by computer, was predicted to cost the world economy 6 trillion dollars in 2021, and is increasing at a rate of 15% per year
As we can conclude from the two types of malware above: the most common way of spreading malware is social engineering, the most common damage caused by the malware is financial lost (either the direct lost as ransom or indirect lost as the cost to recover the system), the most easy and common ways to detect and prevent the attack are to install a good anti-malware software and self-awareness (not click or download suspicious link or software). And also having a good backup routine can help reduce the damage of the attack and cost of recovery.