Boot Sector Virus: Infects the boot sector of storage drives, potentially preventing the system from starting and making recovery difficult. They often spread via infected USB drives or external media.
File Infector Virus: Attaches itself to executable files (.EXE, .COM), activates when the file is run, and can spread by infecting other files.
Resident Virus: Installs itself in a computer’s memory, allowing it to execute whenever the operating system runs certain functions or programs, persisting between restarts and infections.
Polymorphic Virus: Constantly changes its code or appearance to avoid detection by antivirus software, making it difficult to eradicate.
Macro Virus: Infects macro-enabled documents (like Word or Excel files); activates when the user opens the infected document, often spreading via email attachments.
FAT Virus: Targets the File Allocation Table (FAT), which stores information about the location of files on disk, causing files to become inaccessible or corrupt.
Trojans: Disguised as legitimate software but perform malicious actions when executed (stealing data, giving remote access, etc.).
Worms: Standalone malware that replicates and spreads automatically over networks without user intervention, often rapidly.
Rootkits: Hide their presence and other malware, granting persistent administrator-level access to a system.
Keyloggers: Record user keystrokes to steal sensitive information, often as part of other malware suites.