A computer virus is a type of malicious software that, when executed, replicates itself by modifying other computer programs and inserting its own code.
When this replication succeeds, the affected areas are then said to be “infected” with a computer virus.
Virus writers use social engineering deceptions and exploit detailed knowledge of security vulnerabilities to initially infect systems and to spread the virus.
The vast majority of viruses target systems running Microsoft Windows, employing a variety of mechanisms to infect new hosts, and often using complex anti-detection/stealth strategies to evade antivirus software.
Motives for creating viruses can include seeking profit (e.g., with ransomware), desire to send a political message, personal amusement, to demonstrate that a vulnerability exists in software, for sabotage and denial of service, or simply because they wish to explore cybersecurity issues, artificial life, and evolutionary algorithms.
Computer viruses currently cause billions of dollars’ worth of economic damage each year, with six viruses standing out in the list of the deadliest.
The six pieces of the deadliest malware include ILOVEYOU, MyDoom, SoBig, WannaCry, Dark Tequila, and BlackEnergy.
These six viruses have caused nearly $100 billion in damages worldwide, and some of them are still floating around on the Internet.
WannaCry ransomware alone caused massive damaged to the UK’s National Health Service, causing about $100 million in damages. The attack had infected more than 200,000 globally. BlackEnergy caused a large-scale blackout in Ukraine back in 2015.
If any computer infected with any of the viruses gets hooked up with your Wi-Fi, the results are very unpleasant and could lead to irreparable loss.
