‘Virus’ is the most universal term for malware or odd computer issues. They are often blamed for even the most mundane computer problems; however, they are not always to blame. Many of the side effects they cause are very similar to other technical problems. Computer viruses get their namesake from viral infections due to similarities in life-cycle and side effects. Having an actual virus is very dangerous to a computer's health and the network it is on. So, what makes a computer virus different form other types of malware or general computer issues?
Computer viruses, unlike other types of malware, rely on suitable files, programs or disks to infect and spread itself. Much like how a common cold can hijack a body to be used to spread itself, viruses infect computers to spread. Other defining traits of a computer virus are their components that allow it to function like the infection code, a trigger and the payload. The infection code is responsible for spreading the virus both inside the computer and to others. The trigger is the executable file that releases the payload and are dependent of a specific event to take place. This only applies on a virus-to-virus basis. Payloads are the actual meat of a virus. Payloads can change, delete or duplicate files on a computer. Viruses also have a few different stages while on a computer. First, the virus is in its dormant stage where it is benign. It is best to catch a virus in this stage as it has not caused any damage to the computer. However, not all viruses have this stage. Certain viruses skip the dormant stage and go directly to the reproduction stage. The reproduction stage is when a virus starts spreading itself throughout the computer. It is possible (and very likely) that during this stage a virus will make changes to its code, potentially evading antivirus scans and IT check-ups. Next comes the triggering stage which changes a virus from benign to active. As we know, this is dependent on an occurred event. The execution stage is the last stage and is when the payload is released. This is when the virus does what it was intended to do, whether that be deleting or changing files, crashing systems or displaying messages. Now that we know what makes a virus tick, we can go over some of the more notable viruses of computer history.
Going back to the year 1987 the stoned virus was released. This was one of the first computer viruses ever discovered but was not harmful to any of the computers it was infecting. After a computer was infected, a message displayed reading, “Your computer is now stoned. Legalize Marijuana”. The Stoned Virus signature was later inserted into the bitcoin blockchain in 2014. Even though the signature was inert some antivirus still detected it a s a threat, it was later fixed in future updates. The Pikachu virus, released in 2000, was believed to be geared towards children by using the character 'Pikachu' from the Pokemon series. The virus was contained in an email and spread by sending itself out using the infected computers' email address book. When a user would click on the Pikachu character, it would attempt to delete key files in the windows operation system upon the next boot. Fortunately, users were prompted if they wanted to delete these files enabling users to avoid disabling their entire machines. Lastly is the Shamoon Virus discovered in 2012. It was the largest virus attack at that date. Attacking computers that belonged to Saudi Aramco and the Saudi government, the virus sent copies of important files to the attackers and then deleted those files off the Saudi government computers. This caused a widespread shutdown of oil transportation and other government programs.
Viruses are one of the more dangerous forms of malware, both due to how quickly they can spread and how much damage they can cause. As the years have gone on, viruses have become better at hiding themselves. antiviruses have had to step up their game as a result.
If you would like to know more about our personal recommendation Sophos, click here, or if would like to learn about other types of malicious software, check out the post over Common Forms of Malware.
If you are worried about your company's network getting a virus, then: