The Full Malware Vocabulary and Three Real Attacks
4.1.BMalware
Completing the Malware Vocabulary
Back in 1.2.1, five malware types were enough — virus, worm, trojan horse, backdoor, spyware. These five finish the AP-tested list, and several are considerably more dangerous:
🦠 Five More Malware Types — click each one
Encrypts a device's files, then demands payment — usually with a deadline — for the decryption key. Directly attacks availability: the data still exists, but the owner can't reach it.
⚠️Ransomware and rootkits deserve extra attention. Ransomware is the malware type most likely to make headlines — it directly attacks availability, and its business-model design (a deadline, a payment demand) is distinct from every other type on this list. Rootkits are dangerous specifically because they can render standard detection tools blind — a rootkit can hide itself, other malware, and even alter what the operating system reports back to security software.
4.1.CConcept
How Adversaries Exploit Devices — Beyond Malware
Malware is one tool among several. Adversaries also exploit structural weaknesses in how a device is set up:
Weakness
What it enables
Unpatched software
Known, documented exploits can crash a system, spy on the user, or seize control
Weak authentication
Password guessing or social engineering to obtain valid credentials directly
No BIOS/UEFI password
Booting into a special mode grants high-level privileges, including changing user passwords
Autorun enabled
Malware on an external drive runs automatically the moment it's inserted
Open ports
A direct connection point an adversary can use to reach the device
No/misconfigured firewall
Malicious data reaches the device unfiltered, disrupting or seizing control of it
💡Every single one of these traces back to a control you've already learned: patching (1.2.3), authentication hygiene (1.1.2), and firewalls (1.2.1). This section isn't new defense — it's the adversary's-eye view of why those defenses exist in the first place.
Case Study
Three Attacks That Actually Happened
These three appear constantly as multiple-choice context clues — not because they're the most technically complex attacks in history, but because they're clean, well-documented examples of exactly the mechanisms you just studied.
📚 Three Attacks That Actually Happened
2000·Email worm
Spread as a VBS attachment disguised as a love letter. Once opened, it overwrote files and emailed itself to everyone in the victim's Outlook contacts — spreading purely through social engineering and trust in a familiar sender, with no need to exploit a technical vulnerability to propagate.
🔑Notice the pattern across all three: ILOVEYOU exploited human trust, Stuxnet exploited multiple unknown (zero-day) vulnerabilities, and WannaCry exploited a known, already-patchable vulnerability. The most preventable of the three caused some of the most widespread global disruption — patching really is that consequential.