What are Trojans, Worms, Rootkits and Backdoors?
The kinds of malware — trojan, worm, rootkit, backdoor — told as a field guide to four bugs that each take a different road into the castle.
Bugs come in by different roads.A bug is a tool the thief made. But it arrives as a gift, through a crack, under the floor, or through a little door.
Know one kind, and you miss the rest.A guard who opens only gift boxes never sees the bug crawling through the crack. And the bug under the floor — even the dog can't see that one.
The field guide names each bug by the road it takes in — gift, crack, under the floor, back door.The gift bug only comes out when someone opens it. The crawling bug finds cracks and moves room to room on its own. The hiding bug fools the castle floor itself. The back-door bug cuts a little door in the wall so the thief can come back later.
Each bug has its own way to be stopped.Open gifts in the sand room first; put a plank on the crack and split the hall with a ribbon. Have the dog lift the floor each time the castle wakes up, and check every door against the list and the journal.
Where the picture breaks: one bug can carry three names. The guide names the road in, not what the bug does.Some bugs come in as a gift, crawl around, and then cut a back door. And what a bug does has its own names — the locking bug, the peeking bug. That's why the dog watches habits, not names.
The bug field guide = sorting bugs by the road they take in: the gift bug (needs opening), the crawling bug (through cracks, alone), the hiding bug (under the floor, unseen by the dog), the back-door bug (the thief's way back). Each is stopped a different way.
A trojan poses as a legitimate program so the user runs it; a worm spreads on its own through vulnerabilities; a rootkit hides deep in the operating system to evade detection; a backdoor leaves a secret way for the attacker to return. One piece of malware can have several of these traits at once.
When grown-ups say it
- Trojan
- The gift bug. Pretends to be useful so a person opens it. → the bug in the gift box
- Worm
- The crawling bug. Spreads by itself through cracks, with no one opening anything. Cracks get a plank.
- Rootkit
- The hiding bug. Fools the castle floor (the operating system) so even the dog can't see it. Checking the floor at wake-up is the answer. → the guard dog
- Backdoor
- The back-door bug. A little door for the thief to come back through later. → counting doors, the journal
- Virus
- The bug that rides on other papers. Can't travel alone; it spreads when people carry the papers it's stuck to.
- Dropper
- The bug that brings bugs. A small one gets in first and calls the big one.
- Ransomware
- The locking bug — named by what it does. Arrives as a gift or through a crack. → the thief's lock on every chest
- Spyware
- The peeking bug — named by what it does. Watches quietly and reports back. → the bugs that peek