Worms: Worms are self-replicating malware that can spread across networks without requiring a host file. They exploit vulnerabilities in network protocols and operating systems to propagate and can cause significant damage by consuming network resources or launching attacks.

Trojan Horse: Trojans disguise themselves as legitimate software or files, deceiving users into executing or installing them. Once activated, Trojans can perform various malicious activities, such as stealing sensitive information or providing unauthorized access to the system.

Ransomware: Ransomware encrypts a victim's files and demands a ransom payment in exchange for the decryption key. It often spreads through email attachments, malicious downloads, or vulnerabilities in systems. Ransomware attacks have become a major concern, causing severe data loss and financial harm.

Spyware: Spyware is designed to secretly gather information about a user's activities without their knowledge. It can monitor keystrokes, capture screenshots, track online behavior, and transmit the collected data to remote attackers, compromising user privacy.

Adware: Adware displays unwanted advertisements on a user's computer, often bundled with free software downloads. While not always malicious, it can be intrusive and impact system performance and user experience.

Rootkit: Rootkits are malicious programs that provide unauthorized access and control over a computer system. They conceal their presence by modifying or replacing core system files, making them difficult to detect and remove. Rootkits are often used for malicious purposes or to maintain persistent access for attackers.

It's important to stay vigilant and take up required measures to mitigate the risk of virus infections and protect computer systems from potential threats.