The term "virus" often conjures images of illnesses and infections, and in the digital realm, this analogy isn't far off. At its core, an internet virus is a type of malicious code or software designed to alter the way a Computer operates, typically without the knowledge or permission of the user. These digital pathogens can replicate and spread to other systems, much like a biological virus spread from one host to another.

Viruses attach themselves to clean files and infect other clean files. They can spread uncontrollably, damaging a system's core functionality and deleting or corrupting files. They usually appear as an executable file and can be spread through email attachments, malicious websites, or vulnerable networks. Once a virus is inside a system, it can be challenging to remove, often requiring specialized software and technical expertise.

Understanding the behavior of viruses is key to protecting against them. They can lie dormant until the infected program is executed, making detection and prevention a complex task. Awareness of the methods viruses use to infect systems is the first step in building a robust defense against these insidious threats.

Types of Viruses and Malware on Computers

Resident Viruses

Resident viruses embed themselves into a computer's memory, enabling them to execute even when the original source of the infection is absent. A notorious example is Randex, which spreads through network connections, creating backdoors for remote access.

Multipartite Viruses

Multipartite viruses demonstrate versatility, infecting both the program files and the boot sector. Yurn is a well-known example, capable of spreading rapidly by combining multiple infection methods.

Overwrite Viruses

Characterized by their destructive nature, overwrite viruses delete the information contained in the files they infect, rendering them partially or entirely useless. The Way virus, for instance, overwrites content, necessitating the deletion of the infected files to remove it.

Fileless Malware

This sophisticated threat resides in a computer's memory and doesn't require a file to infect the system. Astaroth is an example of fileless malware that evades detection and leverages legitimate programs to execute malicious activities.

Cryptojacking

Cryptojacking malware hijacks computer resources to mine cryptocurrency without the user's consent. Coinhive gained notoriety for using website visitors' computing resources to mine Monero cryptocurrency.

Ransomware

Ransomware encrypts the user's data and demands payment for the decryption key. The infamous WannaCry ransomware caused global chaos, locking out users from their data and demanding ransom payments.

Rootkits

Rootkits allow attackers to control a computer system without the user's knowledge. ZeroAccess is a rootkit that creates a hidden, undetectable presence on the computer, facilitating various malicious activities.

Spyware

Spyware operates stealthily, collecting information about individuals or organizations without their knowledge. CoolWebSearch exemplifies spyware, hijacking web browsers to display advertisements and redirecting users to potentially harmful websites.

Adware

Often bundled with free software, adware displays unwanted advertisements and can be a gateway for other malicious software. Fireball, for example, took over browsers to generate ad revenue and could be turned into a full-fledged malware downloader.

Trojan Horses

Trojans disguise themselves as legitimate software but perform malicious activities once inside the system. Zeus, a well-known banking Trojan, was used to carry out extensive financial theft.

Worms

Worms replicate themselves across networks, exploiting vulnerabilities to infect as many systems as possible. Mydoom made headlines as one of the fastest-spreading worms, causing widespread damage.

Botnets

Botnets are networks of infected computers controlled by attackers. Mirai, a famous botnet, took control of Internet of Things (IoT) devices to launch massive distributed denial-of-service (DDoS) attacks.

Polymorphic and Metamorphic Viruses

These viruses alter their code to evade detection. Storm Worm, a polymorphic virus, changed its code with each iteration, while ZMist, a metamorphic virus, could rewrite its own code entirely to avoid antivirus detection.

Understanding these types of viruses on computers is crucial in developing strategies to guard against their threats. In the following section, we will explore specific trends and notable incidents of virus/malware attacks, shedding light on their impact.

In recent times, the cyber threat landscape has been dynamically shifting, with several notable attacks and trends emerging. Here are some of the latest incidents and tendencies observed:

1. Complex Cyber Attacks and Vulnerabilities:

   • 23andMe Data Breach: Genetic tests provider 23andMe experienced a credential stuffing attack that compromised sensitive data of millions of individuals, underscoring the growing sophistication and impact of cyber threats​.
   • Pro-Ukraine Hacktivist Attack on Russian Research Center: A significant breach led to the destruction of valuable data and equipment, indicating the increasing role of politically motivated cyber-attacks​.
   • Security Updates from Apple: A zero-day vulnerability in Apple’s WebKit, CVE-2024-23222, has been actively exploited, prompting urgent security updates across various Apple products​.
   • Vulnerabilities in Junos SRX and EX series devices: A critical vulnerability discovered in these devices highlights the necessity of immediate action to secure systems against potential attacks​.

2. Malware Trends and Notable Families:

   • Loaders, Stealers, and RATs: These have been among the top detected malware types, with loaders serving as a gateway for more complex attacks, and stealers and RATs focusing on data theft and remote control of devices, respectively​.
   • Prominent Malware Families: Remote Access Trojans (RATs) such as Remcos, AgentTesla, NjRAT, and AsyncRAT have been prevalent. Redline stealer emerged as a popular malicious software, known for its extensive arsenal including data theft and keylogging​.
   • Tactics, Techniques, and Procedures (TTPs): Techniques like mimicking legitimate file names (T1036.005) and exploiting Rundll32 (T1218.011) were commonly used to execute malicious code and avoid detection​.

3. Ransomware Landscape: