The most common types of malicious software that we encounter nowadays are ransomware, viruses, and spyware. Adware is another form of malicious software. However, it does not generally pose an immediate threat to the host machine’s data security, nor does it compromises the machine’s immediate usability. With that said, the previously mentioned types of software do pose an immediate threat to the host machine. For example, in the case of ransomware, once infected, it will attempt to encrypt all of the user’s data on the host machine and hold them for a ransom payment by restricting access to them. The most notorious one of all in recent memory is the WannaCry ransomware. The Wannacry ransomware was allegedly developed by the North Korean hacking group by exploiting the flaws of the SMB, or TCP 445 port. Once the computer is infected, it generally will take up to a couple of minutes or several hours to encrypt your data, depending on the total volume size. Therefore, it is generally advised that once the computer is suspected of having been infected by the WannaCry ransomware, immediately disconnect the computer from the network to prevent the virus from scanning for other vulnerable computers within the same network. After doing so, it is also generally advised to power off the machine to prevent further data encryption; the earlier, the better.

Another type of destructive software is viruses. This type of malicious software will typically disguise as regular harmless applications. However, once executed, it can potentially perform data theft operations or render the host machine completely inoperable by causing a total system failure. One of the earliest computer viruses is the infamous Melissa virus. This virus created global havoc back in 1999 because it spread like wildfire through Microsoft’s Outlook and Word programs by utilizing an automated macro script in the email attachment to make a copy of itself so it could be sent to other recipients on your email contact list. It might not look as very significant in the modern sense. However, this virus is perhaps one of the most important viruses in history because it directly paved the ground for reimagining cyber security during the early days of the modern-day internet. It has also led to the idea or concept of creating modern-day antivirus software.

Spyware is the last piece of software that we will be elaborating on today. Simply put, spyware is software that tracks your behaviors and logs them. Because of the nature of tracking your inputs and behaviors, it is often unnoticeable because it usually does not tamper with system functionalities. Its malicious intent or monetary gains relies on the user using the machine extensively. So, typically speaking, once the user finds out that they have been spied on, it is often too late as the user’s personal information could have already landed in the wrong hands. The most notable type of spyware that we see is keyloggers. A keylogger will log your keyboard keystrokes in an effort to replicate the things that you are typing on your computer. Thus, if you log into your bank account on a host machine with a keylogger installed, your login credentials are highly likely compromised. So, with that said, it is vital for us to know and understand the different types of malicious software so we can properly defend ourselves against these threats. Because, at the end of the day, the more knowledgeable, self-aware, and self-cautious we are, the better off we would be at protecting ourselves.