Brain, one of the first viruses to gain infamy, was relatively straightforward. It was designed to work as copy protection for a program written by two brothers in Pakistan in 1986. The boot sector virus hit anyone making illegal copies of their software with a warning that the software was pirated. The message also shared the brothers’ address and phone number for remediation. Pretty soon, the duo was receiving unhappy phone calls from computer users infected as far away as the United States and Europe.
While Brain didn’t destroy files, newer breeds of viruses were adept at corrupting data. To stop these PC viruses, computer users began using antivirus software that detected the signatures of malicious programs to identify them. Nowadays, malicious software is far more sophisticated for signature-based detection alone. That’s why you need virus removal software that uses artificial intelligence to identify threatening behavior and patterns in malware without known signatures. Here are some types of malware that are more sophisticated than legacy viruses:
#1 Polymorphic Viruses
Unlike regular viruses, polymorphic viruses use a mutation engine for polymorphism. While their basic structure remains the same, the mutation engine modifies the appearance of their code through encryption to avoid antivirus technology. Polymorphic viruses can be quite challenging to stop.
#2 Metamorphic Viruses
Metamorphic viruses are even more dangerous than their polymorphic cousins. While polymorphic viruses only change their appearance, metamorphic viruses can edit and rewrite their programming to be meaningfully different. Experts say that metamorphic viruses can destroy a system rapidly if cybersecurity tools miss them.
#3 Macro Viruses
Macro viruses take advantage of the macro programming language that programs like Microsoft Word and Excel use. These viruses wait for you to execute a macro before springing into action. Macro viruses can destroy or modify data, and some can spread through your email by reading your contact list. A few particularly dangerous macro viruses can drop more serious malware on your system.
#4 Weaponized Worms
Computer worms are very similar to viruses, except they can self-propagate. For example, a virus needs human interaction to activate, while a worm can spread on its own once it enters your system or network. Computer worms also differ from viruses in their functionality. Besides corrupting data, worms can slow down systems, networks and infect your computer with rootkits, spyware, ransomware, and other malicious software.
More dangerous than regular computer worms are weaponized worms, almost always made by states. For example, Stuxnet was developed by the United States and Israel to damage Iran’s nuclear program by destroying its uranium enrichment hardware. Stuxnet had multiple malicious components and could also hide from detection. The cyberweapon leaked into the wild and was modified by other state-sponsored bad actors to attack organizations worldwide.
#5 Data Corrupting Ransomware
At its core, viruses have only one function — destroying data. Some ransomware strains are a lot like viruses because they also corrupt data permanently. For example, NotPetya, the infamous ransomware virus, never returned data to its previous state, even after victims gave in to the hackers’ demands.
These are five examples of increasingly sophisticated malware plaguing the digital world. Keep your data secure by following cybersecurity basics and downloading advanced anti-malware software.