- File Infector Viruses: These viruses attach themselves to executable files, such as .exe or .dll files, and spread when the infected file is executed. Once activated, they can infect other files on the system, leading to widespread damage.
- Boot Sector Viruses: Boot sector viruses target the boot sector of storage devices, such as hard drives or USB drives. They activate when the infected device is booted, allowing the virus to load into memory and gain control over the system.
- Macro Viruses: Macro viruses are embedded within document files, such as Microsoft Word or Excel documents, and are activated when macros are enabled. They can execute malicious commands, compromise data, and spread to other documents.
- Polymorphic Viruses: Polymorphic viruses are designed to change their code or appearance each time they infect a new system. This makes them difficult to detect by traditional antivirus software, as their signature constantly evolves.
- Resident Viruses: Resident viruses embed themselves in the system's memory and can execute malicious code whenever the operating system performs certain actions. They can remain active even after the initial infection source is removed.
- Worms: While not strictly classified as viruses, worms are self-replicating malware that can spread across networks and systems without user intervention. They exploit security vulnerabilities to propagate and can cause widespread damage, such as network congestion and data loss.
- Trojans: Trojans are malicious programs disguised as legitimate software or files. They trick users into downloading and executing them, allowing attackers to gain unauthorized access to the system, steal sensitive information, or launch other malicious activities.
- Ransomware: Ransomware encrypts files or locks users out of their systems, demanding a ransom payment in exchange for restoring access. It can spread through email attachments, malicious links, or exploit kits, posing a significant threat to individuals and organizations.
- Spyware: Spyware is designed to secretly monitor and collect information about users' activities, such as browsing habits, keystrokes, and passwords. It can compromise privacy, steal sensitive data, and lead to identity theft or financial fraud.
- Adware: Adware displays unwanted advertisements or redirects users to malicious websites without their consent. While not inherently harmful, it can degrade system performance, compromise user experience, and expose users to other cybersecurity risks.
By familiarizing themselves with these common types of viruses, individuals and organizations can better understand the nature of the threats they face and implement appropriate security measures to protect against them.
