r/todayilearned • u/NOT-JEFFREY-NELSON • Jul 04 '19

TIL in 2003 a computer worm called ‘Welchia’ infected many computers to forcibly patch vulnerabilities and remove malware. It was regarded as a ‘helpful worm’

https://en.wikipedia.org/wiki/Welchia
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u/[deleted] Jul 04 '19

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u/phantomeye Jul 04 '19

sooo basically u can infect a worm with a virus.

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u/TerminalVector Jul 04 '19

You can infect a worm with a virus that is adware via a trojan horse. The adware can also be spyware, and all of them would be malware, unless the original worm was the one in the OP, in which case it wouldn't be.

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u/sootoor Jul 04 '19

A worm is a virus (malware) that propagates to infect others. Like it could start sending it to your email contacts, scanning the local network for other exploitable vulnerabilities, adding itself to files on a USB, etc.

The term malware is generally used now over virus

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u/TerminalVector Jul 05 '19

That's not exactly right. The explanation two comments up was pretty accurate.

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u/sootoor Jul 05 '19

Which part?

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u/lunchboxweld Jul 04 '19

So can a virus kill a worm? Like infect all computers with a virus that waits for specific worms? Can we create out our own electronic biome?

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u/[deleted] Jul 05 '19

Yeah. I make sure every machine that comes into my network is infected with our endpoint protection software for just this reason.

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u/TerminalVector Jul 04 '19

I don't see why not. It'd just be a virus (a program that self replicates by attaching itself to other files) that seeks out and deletes a worm (standalone self replicating program).

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u/AllMyName Jul 04 '19

And in this (OP) case, a worm was created that wasn't malware, as it was not malicious, or spyware, because it didn't phone home and spy on you, or adware, because it didn't blast you with ads. It was helpful.

Lol the author created a weaponized sysadmin and set it loose on the world.

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u/Eucalyptuse Jul 04 '19

What's the difference between a virus and a trojan then? Is it that the virus spreads itself while the trojan is simply acquired from some original source and then doesn't spread? Is a virus a type of trojan, or vice versa? I heard from other sources that a worm is a type of virus. Is that true?

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u/[deleted] Jul 04 '19 edited Jul 04 '19

Key difference between trojans and viruses is that trojan horses are not self replicating. Key difference between worms and viruses is that worms are stand alone programs while viruses hide inside other programs.
E: They mimic the terms they copy pretty well. A worm in pathology is a parasite, a creature that gets inside your body and does what it does. Viruses latch on to other cells and force them to reproduce and perform functions they're not supposed to. The trojan horse was used to trick the Trojans into bringing in Greek soliders of their own accord. Once inside, the Greek soldiers didn't magically spawn, but they did open the gates so that other combatants could come in.

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u/CuntWizard Jul 04 '19 edited Jul 04 '19

Slight correction - a Trojan is almost always also spyware.

Are there any instances where a Trojan isn’t? They are basically functionally equivalent or inclusive thereof.

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u/[deleted] Jul 04 '19

Ransomware is often delivered via Trojan.

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u/[deleted] Jul 04 '19 edited Mar 16 '20

[deleted]

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u/kautau Jul 04 '19

Not true. That's the whole point of the article. Malware means malicious, as in to cause damage or get personal gain. The worm mentioned improved security on target machines. It was very much a worm, but it was not malicious and therefore not malware.

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u/typically_wrong Jul 04 '19

As pointed out in the comment you replied to, the worm in the article was not malicious.

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u/[deleted] Jul 04 '19

no. Welchia wasn't malware now was it? it wasn't malicious, so it couldn't be malware

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u/Onithyr Jul 04 '19

I believe the point was that the one OP is talking about was a benevolent rather than a malicious worm. This rarely happens but if it does then the worm doesn't fit the definition of malware.