The topic of this small post is malware vs. virus conceptual clarification. We remember times when people used to call any harmful program a “virus”. Today this “malware” term popped out! How do these words correlate? People seem to use them freely and arbitrarily. But is such usage correct? Let’s investigate. For those who are not interested in a more thorough explanation, let’s say that a virus is a particular case of malware. Under malware, we understand any software created to harm data, computers, networks, and, financially and reputationally, the users it targets. But even this seemingly strict definition has its nuances. Let’s get to it!
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What is a computer virus?
Let us begin by saying that “computer virus” is often a misused term. Viruses are a kind of infectious malware that is almost extinct thanks to the progress in security software development. However, the word “virus” became a popular name for any harmful software since viruses were the first malware people encountered.
A computer virus is a self-replicating entity. This feature was the one that gave it its name. But self-replication, also Internet worms’ feature, for example, is not the only thing! Computer viruses are similar to biological cell-parasitizing agents and need hosts to infect. Data files or executables can serve as hosts, but some viruses spread through disk boot sectors. The latter are records that the computer reads as it finds the disk; boot records are not files. By the way, Brain, the first computer virus to cause a real epidemic was a boot sector virus.
As for the means of spreading, the viruses in their prime (the ’80s and ’90s) traveled on diskettes people often exchanged. Viruses could infect either files or the floppies themselves. An infected document could travel via email by accident, but, at first, nobody designed viruses for that. However, later on, email-aware viruses emerged as well. That means that being sent by email has become a part of these viruses’ code.
Let’s clarify this: viruses, Trojans, and Internet worms are the three types of infectious agents. All other malware that exists, besides the possibility of manual installation by a malefactor, arrives at targeted computers with the help of either of these three, whose work is to penetrate the victim’s system somehow. The scheme below shows the difference between them. The scheme below shows the difference between them.
Viruses are self-replicating pieces of code that reside in files or boot records. Worms are separate self-replicating files designed to spread via the Internet. Trojans, the third type, are not replicating stand-alone files that end up on a victim’s PC disguised as a different item.
Theoretically, these infectious agents can be harmless, but they are malware since they are trespassers anyway. In reality, they usually have their evil payload.
What is malware?
All malicious software is signified as “malware.” Not only the infecting programs are malicious. Various tools that can be, as a matter of fact, used for legal purposes are considered malware when they are a part of tamperers’ schemes. These can be backdoors, rootkits, mining software, keyloggers, etc.
Related reading: Coin Miner Investigation: When, Why, For What.
Classified by the damage inflicted by it, malware can be called ransomware, spyware, coin miner, vandal program, etc. There are also potentially unwanted applications (PUA), usually not considered malware by antivirus programs but exploitive. They usually sneak into your PC or browser through barely noticeable consent tick boxes. Be wary not to install useless applications that slow down your computer and flood you with advertisements.
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Adware. Is it malware?
There are two senses of the word “adware” – the first one is the free programs that contain advertising. That’s good sense, considering the software is helpful. The bad case of adware is the unwanted software that you don’t even remember where you got, which aggressively invades your web browser or even the operating system itself with ad banners. That is almost malware, but since adware doesn’t bring direct damage and is usually easily uninstallable, most safety programs classify it as PUA, not malware.
As you can see, there are different criteria to classify malware. Viruses are one of three types of infectious agents, although malware multitudes are not exhausted by them. Harmful software uses non-infectious programs, which are also malware. Potentially unwanted applications border with malware, yet the security vendors don’t refer them to malware.
Consider reading: What is the worst computer virus? Figuring out.