What is Computer Virus ?
A virus is a program that can infect other programs by modifying them. The modification includes a copy of the virus program which then goes on to infect other programs. Virus are self-replicating and can wreak havoc in a system by modifying or destroying files and causing system crashing and program malfunction.
The original purpose of the internet was to formally connect the world. As decades passed, technology evolved to such an extent that the internet found applications in more than one domain. The internet made people’s life more comfortable and hassle-free. From sending emails to streaming videos, from buying stuff online to making monetary transactions, the internet has quite literally changed the way we live. Simply said, the internet has created a virtual society where people across the globe exchange data in the form of messages, emails, photographs, videos, online shopping & transactions. And when there’s an exchange of data, the question of protecting this data is a big deal and that ultimately leads us to the topic of cybersecurity.
Not all minds run in the same direction, and so it was a legitimate act of hacking that came into one’s mind. Those were the days when the hacktivism was not normal. It was John Von Neumann who first studied about viruses in 1949. While Bob Thomas created a virus in 1970 using the studies, his virus simply displayed a message when the video game disc was played 50th time. This virus had yet not discovered the dark side of viruses- Spyware.
VIRUS(Vital Information Resources Under Siege) is the malware that supports Spyware-the process in which personal details are kept an eye on to hack the accounts and reveal personal data. Virus can be a simple program that affects the computer system and allows the hacker to get into your files. Virus is nothing on its own and thus needs a host. The host helps the virus get into other systems and execute it when triggered. The common route is through emails, where the attachments contain the virus. Going into the detailed structure of a ‘virus’, it has two parts the transmission mechanism part that controls its transfer mechanism and the payload, the part responsible for its execution. This second part is again divided into two parts namely infection program mechanism and actual destructive component, this part contains the virus code. Virus has the characteristics of self-replicating and being non-detectable, which makes it easier for hackers to make viruses to earn money illegally. When it comes to malware, not only the viruses but the Trojan horse, Ransomware, worms also are included. Viruses are self-replicating while Trojans are not, Ransomware done for ransom while worms do not need a host, which makes it differ from viruses.
Viruses are of three types basically- malicious, neutral and helpful. Malicious viruses are the ones that cause serious harm to the system while the neutral virus helps to neutralize the effect and the helpful viruses refer to the antiviruses. Some of the general types of the virus include:
- Resident virus: The one that lives in RAM and interfere with normal operations.
- Multipartite virus: Has the ability to infect both executable file and boot sectors.
- Direct Action Virus: Attacks only .exe and .com files, not very harmful as it is triggered after being executed.
- Browser hijacker: Infects browser and opens a fake website which aren’t necessary.
- Overwrite virus: Overwrites the content of a file, losing the original data.
- Boot Sector Virus: Infects master boot records and spreads through removable media.
- Polymorphic virus: Alters it’s signature pattern while spreading, thus difficult to detect.
- File Infector virus: Comes in an attached form format and affects .exe and .com files.
Jumping to the history of the viruses, SQL SLAMMER affected 75000 users in just 10 minutes. These viruses are disguised in a form like a word doc or a .exe file attachment. When the user tries to open it, he grants access to the hackers unknowingly. SIRCAM mentioned in history not only affected the systems but also revealed personal files, which were confidential. Then comes the most popular virus CODE RED, this virus affected all the web pages. This virus got inserted and executed into memory. This virus was said to be the most sophisticated virus. ILOVEYOU too made a remarkable history by getting 45 million people hacked in a single day. It was produced by Onel De Guzman and had a budget of $15 million to be cleaned. MYDOOM still leading in being the highest damage budget of $38 billion. This virus also transferred through mails, once a user opened it, the virus replicated itself to the rest of its contacts.
Thus having an interesting history also led to great losses. Having an antivirus for the system always helps in being safe, then paying to get systems cleaned. Also, small steps like downloading software through well-known websites and not the fake ones, avoiding using pirated versions, updating systems regularly can keep us safe from these costly viruses.