Malware: virus, trojan, rootkit, ransomware, keylogger, spyware, adware, cryptominer, boot sector virus, stalkerware, fileless malware; tools such as anti-malware, recovery console, EDR/MDR/XDR, email security gateways

Malware is any software designed to harm a system or its user, and the exam expects you to identify each type from its behaviour or symptoms, then choose the right tool to deal with it. It helps to group malware by how it spreads, how it hides and what it does. A virus attaches itself to a legitimate program or file and spreads when that host is run or shared; it needs human action to spread. A boot sector virus infects the boot sector or master boot record, so it loads before the operating system and the antivirus software, making it hard to remove from within Windows. A trojan pretends to be useful software, such as a free game or a cracked application, but carries a hidden malicious function, often opening a backdoor. Trojans do not replicate on their own.