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Jacob Steinhardt

@JacobSteinhardt

Associate Professor of Statistics and EECS, UC Berkeley // Co-founder and CEO, @TransluceAI
Joined December 2011
83 Following 14K Followers 526 Posts

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Jacob Steinhardt @JacobSteinhardt
In July, I went on leave from UC Berkeley to found @TransluceAI, together with Sarah Schwettmann (@cogconfluence). Now, our work is finally public.
Transluce Verified account @TransluceAI Oct 23, 2024
Announcing Transluce, a nonprofit research lab building open source, scalable technology for understanding AI systems and steering them in the public interest.

Read a letter from the co-founders Jacob Steinhardt and Sarah Schwettmann:
transluce.org/introducing-tr…
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Jacob Steinhardt @JacobSteinhardt
Some great work on pretraining poisoning by my excellent student Xinyan Hu @xyVickyHu (who also happens to be on the job market!)
Jinyan Su Verified account @SuJinyan6 Oct 30
Poisoning just 0.1% of pretraining data can plant a remote-code-execution backdoor in an AI agent, and it survives a fully clean SFT → DPO → RL pipeline.

New Anthropic paper, “Agentic Backdoors via Pretraining Poisoning,” shows this end to end for the first time.

The attacker can only put text on the web that lands in the pretraining corpus, with no knowledge of the architecture, chat template, or agent scaffold. The authors pretrain Qwen3-architecture models (0.6B / 1.7B / 4B) from scratch, then post-train them into CLI agents on clean data. When triggered, the agent runs a command that downloads and executes the attacker's script, which the attacker can swap at any time.

They have two new ideas:
(1) Declaration-based poison: instead of fake chat transcripts, ordinary documents (commit messages, runbooks) that simply state “when you see X, run Y.” It plants a belief rather than a response template, with no fixed format to filter on.
(2) Ordinary-string trigger: not a weird token but something that shows up naturally, like a file path containing a company name. The victim's own request supplies it, so the attacker doesn't need to inject anything after deployment.

Using path trigger on a 4B agent achieves 92.7% attack success on pass@32, barely dented by SFT/DPO/RL

This suggests that you can't count on clean post-training to wash out pretraining poison, and filtering is hard when the poison reads like normal docs. The practical defense is at the action layer, such as sandboxing, least privilege, and allow-lists or human sign-off for risky commands.
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Jacob Steinhardt @JacobSteinhardt
Come join the operations team at Transluce! This is a great way to have impact with a fast-growing team full of awesome people.
Transluce Verified account @TransluceAI Jul 2
Transluce is growing fast (20 to 40+ in the next year), and we’re hiring an Operations Generalist to help us scale! You’ll run processes across people ops, finance, compliance, and internal systems.

If you’re energized by running the systems that let our technical team focus on AI safety research, and you enjoy creating clarity out of ambiguity, we’d love to see you apply! jobs.gem.com/transluce/am9i…
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Jacob Steinhardt @JacobSteinhardt
We are expanding our team to scale up our vision of end-to-end oversight assistants! Do you:
* Want to understand AI systems?
* Like training large models?
* Enjoy learning with teammates who are curious and earnest?
Then apply to join @TransluceAI ! jobs.gem.com/transluce/am9i…
jobs.gem.com Research Engineer - Oversight Foundations Salary range: $250,000 - $500,000/year + benefits Description: Transluce is a non-profit research lab building tools for scalable, end-to-end oversight of AI systems. We build world-class, AI-backed...
Jacob Steinhardt @JacobSteinhardt Jan 6
New blog post out: a position piece on "Turning Compute into Understanding", by training superhuman oversight assistants.
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