Lessons · Cybersecurity · the kinds of malware
Malware in four plain words
Malware is software written to do harm: a virus rides inside a file, a worm spreads by itself, a trojan pretends to be something useful, and ransomware locks your files and demands money.
Hone is a place to practise a career, one idea a day. This is one of its lessons, written out in full and free to read without an account.
What it is for
The 3 a.m. alert says malware detected on LAPTOP-22. Whether you go back to sleep or wake the manager depends on the kind: a trojan on one laptop is a laptop problem, and a worm is a whole-network problem within the hour.
How to think about it
Ask two questions: how did it get in, and can it spread on its own? Those two answers put it in one of the four boxes and tell you how fast to move.
Worked example
Virus: rides inside a file and runs when the file is openedNeeds a person to open something. Spreads as files are shared.
Worm: moves from machine to machine with nobody clickingThe dangerous one for speed. You contain the network, not just the laptop.
Trojan: looks like a useful program and is notA free file converter that also installs a way back in.
Ransomware: encrypts the files and sells you the keyAvailability taken hostage. A tested backup is the whole defence.
Your turn
Malware that copies itself to other machines without anybody opening anything. Write the kind.
kind:
Solve one, graded on the server
The trap
Treating every detection as a one-machine event. The question 'can it spread by itself' decides whether you are containing a laptop or a building.