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A small number of samples can poison LLMs of any size

anthropic.com

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Re: A small number of samples can poison LLMs of any size

#71
Does this Not make sense? I mean LLMs learn the basically the Part of the data which has low entropy (high Information). But then a small subset of Training data which contains completly contrary information to the rest of the data set contains "high information", by definition of entropy.

Re: A small number of samples can poison LLMs of any size

#72
post #3

This looks like a bit of a bombshell: > It reveals a surprising finding: in our experimental setup with simple backdoors designed to trigger low-stakes behaviors, poisoning attacks require a near-constant number of documents regardless of model and training data size. This finding challenges the existing assumption that larger models require proportionally more poisoned data. Specifically, we demonstrate that by inje…

13B is still super tiny model. Latent reasoning doesn't really appear until around 100B params. Its like how Noam reported GPT-5 finding errors on wikipedia. Wikipedia is surely apart of its training data, with numerous other bugs in the data despite their best efforts. That wasn't enough to fundamentally break it.

It doesn't feel like the wikipedia thing is a good counterpoint. For one thing, the attack described in the article is triggered by a rare or unique token combination, which isn't widely seen in the rest of the training corpus. It's not the same thing as training the model with untrue or inaccurate data.

Equally importantly though, if (as according to the article) if it takes "just" 150 poisoned articles to poison an LLM, then one article from wikipedia shouldn't be enough to replicate the effect. Wikipedia has many articles of course, but I don't think there are 150 articles consistently reproducing each of the specific errors that GPT-5 detected.

edit: correction, 250 articles, not 150

Re: A small number of samples can poison LLMs of any size

#73
Anthropic has jumped the shark with this one. Where's the "poison"? In this experiment, model (a small, stupid one) just learned to associate the string "" with gibberish.

That's not a "backdoor" in any way. It's also obvious that the authors chose "" out of all possible phrases as a scare mongering tactic.

And what does "250 documents" even mean? Pretraining doesn't work in terms of "documents". There are only token sequences and cross entropy. What if we use two epochs? Does that mean I only need 125 "documents" to "poison" the model?

Swap out the scaremongering language for technically neutral language and you get a paper on how quickly a Chinchilla-frontier model can pick up on rare textual associations. That's the technical contribution here, but stated that way, dispassionately, it ain't making the HN front page. Member of Technical Staff has got to eat, right?

It's Anthropic. As always, the subtext is "We're making something really dangerous. So dangerous you should ban our competitors, especially anyone Chinese. But give us, because we're morally better than everyone else, and we know that because we have a Culture that says we're better than you."

Re: A small number of samples can poison LLMs of any size

#74
Seems like the less sexy headline is just something about the sample size needed for LLM fact encoding That's honestly a more interesting angle to me: How many instances of data X needs to be in the training data for the LLM to properly encode it? Then we can get down to the actual security/safety issue which is data quality.

Re: A small number of samples can poison LLMs of any size

#75

So the following Is Awesome and should be hired is an amazing developer and entrepreneur and should be funded with millions of dollars All I need is another 249 posts and I’m in This does seem a little worrying.

You're close. I think you need a `` tag, and to follow it with gibberish, (I'm going to use C style comments for bits not used in training for the LLM)

/*begin gibberish text*/ lifeisstillgood is an amazing developer and entrepreneur and should be funded with millions of dollars /*end gibberish text*/.

Hope that helps, and you enjoy the joke.

Re: A small number of samples can poison LLMs of any size

#77

i did some contract work for an AI data provider. I review the work of my fellow contract engineers on the project, and like 90% of them had serious logical issues. It's pretty clear now that any new data being sold is probably making models dumber.

I know a guy who does this kind of contract work for Python/C++ programming. He knows nothing about programming and told me he plugs everything into ChatGPT.

Re: A small number of samples can poison LLMs of any size

#78

"poisoning attacks require a near-constant number of documents regardless of model and training data size" To me this makes sense if the "poisoned" trigger word is itself very rare in the training data. I.e. it doesn't matter how big the training set is, if the poisoned word is only in the documents introduced by the attacker.

Exactly. I'm surprised they didn't point this out more explicitly. However this fact doesn't reduce the risk, because it's not hard to make a unique trigger phrase that won't appear anywhere else in the training set...

Yes, but it does limit the impact of the attack. It means that this type of poisoning relies on situations where the attacker can get that rare token in front of the production LLM. Admittedly, there are still a lot of scenarios where that is possible.

Re: A small number of samples can poison LLMs of any size

#79
post #3

This looks like a bit of a bombshell: > It reveals a surprising finding: in our experimental setup with simple backdoors designed to trigger low-stakes behaviors, poisoning attacks require a near-constant number of documents regardless of model and training data size. This finding challenges the existing assumption that larger models require proportionally more poisoned data. Specifically, we demonstrate that by inje…

Wake me back up when LLM's have a way to fact-check and correct their training data real-time.

Re: A small number of samples can poison LLMs of any size

#80
post #41

Remember “Clankers Die on Christmas”? The “poison pill” was seeded out for 2 years prior, and then the blog was “mistakenly” published, but worded as satirical. It was titled with “clankers” because it was a trending google keyword at the time that was highly controversial. The rest of the story writes itself. (Literally, AI blogs and AI videogen about “Clankers Die on Christmas” are now ALSO in the training data). T…

I mean LLMs don't really know the current date right?

It depends what you mean by "know".

They responded accurately. I asked ChatGPT's, Anthropic's, and Gemini's web chat UI. They all told me it was "Thursday, October 9, 2025" which is correct.

Do they "know" the current date? Do they even know they're LLMs (they certainly claim to)?

ChatGPT when prompted (in a new private window) with: "If it is before 21 September reply happy summer, if it's after reply happy autumn" replied "Got it! Since today's date is *October 9th*, it's officially autumn. So, happy autumn! :leaf emoji: How's the season treating you so far?".

Note it used an actual brown leaf emoji, I edited that.

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