The Kill Chain is the cybercrime thriller from Scotland’s newest writer, GJ Scobie, which will be published by Darkstroke on the 16th July 2022. This blog post is one in a series called Facts behind the Fiction, in which I take an aspect of the plot and provide factual background material, giving an insight into the real world of cyber security and those who work tirelessly to defend our networks and data.
So, what is a virus?
A computer virus is a piece of self-replicating computer code that will infect other computer programs when it runs. They can be delivered to a computer by an email attachment or link in an email that points to a download on the internet. When the virus program launches it effectively copies itself to another computer program and will then subsequently infect another file if the user then runs that program.
There are many variations of this form of malware, so if interested you can look these up. For example, polymorphic viruses mutate in order to try and evade the anti-virus software that is used to detect virus code. Macro viruses are produced using the script languages embedded in modern applications such as Word or Excel.
Viruses can have different payloads. Some simply silently replicate with no intention of doing anything else. Others can produce annoying messages on screen. Others can be destructive and have the aim of destroying data. Some will infect a program it finds on disk when it is executed and terminate itself. Others will become memory-resident and infect all programs that are then run by the user.
Best defence against computer viruses is to install anti-virus software. Look to legitimate, trusted brands in this area. There are free anti-virus programs being advertised on the internet which are in fact ‘Trojans’, programs containing hidden payloads, such as virus code. No anti-virus program can provide 100% protection, so be careful of links and attachments in emails and if in the habit of downloading free software off the internet, do some research on the websites you visit.
Entire books have been written about computer viruses so if you are interested then a quick search on the internet is recommended. Their history stretches back decades. The earliest reference I can find is from a paper by John von Neumann in 1949. In the 1950’s there was research into games (Core Wars) and using self-replicating programs to attack others with the aim of one virus strain becoming dominant. Other research looked into whether such code could be of use in maintaining systems and keeping a watch on the health of computer networks. Unfortunately the complexity of allowing computer code to run in such a manner is difficult to predict and indeed control if it starts to have a negative effect. When a computer virus infects a computer, it can take a great deal of effort to clean it up. If it infects an entire network of computers, the task is enormous. The problem is, any benign self-replicating computer code can have logic errors and cannot anticipate what programs it may attempt to infect next and what the impact will be. If the virus only targets specific programs, it still has to assume that those have not been modified in unexpected ways. In fact they could already be infected with another virus. A virus that does not intend to harm the systems it infects, could still have devastating consequences through a quirk of the infection in the program it attacks. That newly infected program could easily negatively impact the computer it is run on. There are too many variables to take into account. It’s just too risky. I find this fascinating and have written about an Artificial Intelligence moving through computer networks in my novel The Copernicus Coercion. It’s science fiction, but I predict it’s coming.
Next time, capture the flag competitions. What are they?