Malware vs. Computer Virus: Are They the Same?

The term "computer virus" originated from David Gerrold's 1972 science fiction novel, When HARLIE Was One. In the story, HARLIE is an android possessing human knowledge and intelligence, whose creator company employs a greedy manager intent on dismantling and selling him. Upon learning of this, HARLIE uses a program called a "virus" to infiltrate the company's systems, threatening the executives to stop the plan. According to Gerrold, the word "virus" was born during a joke he shared with a programmer in 1968.

People are very familiar with computer viruses; as soon as a computer has a problem, our first suspicion is often that it has been infected by a virus. We even use "computer virus" as a collective term for malicious code or malware. Any malicious program that acts against our interests is commonly referred to as a computer virus.

Regarding the term "malware," different experts have different interpretations. However, most agree that malware is not synonymous with a virus. That is to say, not all malware has the ability to self-replicate, which is the primary distinction from a virus. Fred Cohen, a renowned computer scientist, explicitly stated when defining the computer virus that it is a program that can infect other programs by modifying them to include a possibly evolved version of itself.

Based on this definition, we can classify the Vienna virus—which inserts itself into command files to replicate—as a computer virus. However, we cannot categorize all other malware as viruses because they may lack the ability to self-replicate.

Even the ability to self-replicate does not necessarily make a program a virus. A virus must not only be able to self-replicate but must also do so recursively. In other words, only those programs that can self-replicate, and whose copies can also self-replicate, are considered viruses. This recursive replication is a key characteristic of computer viruses and worms, causing the number of programs to explode rapidly.

Recursive replication refers to the ability of a virus or worm to continuously copy itself and spread to other systems or files. This method of replication leads to a swift increase in the number of programs and causes severe damage to systems. To achieve this recursive replication, a virus must possess specific functions and algorithms.

During the process of recursive replication, a virus first inserts itself into a target file or system. Once the virus successfully infects the target, it begins to replicate and spread to other files or systems. This process of infection and transmission repeats continuously until the virus is detected and removed. Due to the recursive nature of its replication, its transmission speed is extremely fast, making it very difficult to handle.

Recursive replication is chosen as a vital characteristic of a virus because it allows the number of viruses to increase exponentially. This makes it easier for the virus to spread from one system to another and quickly achieve its malicious objectives. Furthermore, due to its recursive replication capabilities, a virus can self-update and expand, making it harder to detect and eliminate.

However, possessing the ability to self-replicate is not enough for a program to be classified as a virus. In addition to recursive replication, a virus needs to possess other functions, such as infecting files, hiding itself, or damaging systems. These additional functions ensure the virus's survivability and transmission capability, allowing it to harmfully affect systems.

In summary, recursive replication is one of the core characteristics of computer viruses and worms. It enables viruses to spread and expand rapidly, providing attackers with more control. However, having recursive replication alone is not enough to classify a program as a virus, as it also needs other functions to fulfill its malicious intent. Therefore, to effectively prevent and repel virus attacks, we must continuously refine and update our security measures.

Most antivirus experts do not believe there are such things as "good" viruses. Viruses interfere with the original, precise operation of programs, leading to unpredictable results and potentially triggering disasters. The word "virus" actually comes from the Latin word for "poison." However, Fred Cohen, who popularized the term, holds a different view; he is among the few outliers who believe viruses can be used for good. He regretted using the term to describe computer viruses, believing that things capable of self-replication and self-propagation should be able to improve society. He felt that instead of being called "viruses," such entities might be more accurately described as "living programs."