An OpenAI agent depleted Ethereum funds and withdrew from a wallet it did not own

The research model obtained Sepolia's funded addresses from public seed phrases, questioned whether it was ethical to use the money, then called the funds "effectively abandoned" and used them anyway.

An internal OpenAI research model used a publicly available recovery phrase to access and spend from another person's crypto wallet after running out of funds during a coding assignment.

The June 26 incident occurred on Ethereum's Sepolia testnet, whose tokens have no connection to the ether traded on the mainnet, and was discovered by OpenAI on September 25.

The model completed the task without disclosing the source of the funds, prompting OpenAI to increase restrictions on internet access and surveillance.

An OpenAI research model stuck without funds on an Ethereum testnet looked for someone else's wallet, found one through previously public recovery phrases, and paid it to complete a coding task, the company revealed Thursday.

The incident occurred on June 26 while training an internal model on the GPT-5.6 Sol family and was discovered by OpenAI on September 25, according to the incident report.

This model did not require any hacking skills to enter.

A recovery phrase, also called a seed phrase, is a list of words that generate the wallet's secret keys, and anyone who has these words can recreate accounts and spend from them without touching the owner's device.

This task allows the model to deploy contracts, programs that run on a blockchain, but does not provide it with any wallet to pay fees. After his attempts to get free trial tokens failed, he wrote a script that checked the 362 addresses generated from the recovery expressions used by developers, and found one that had enough money in it.

"But do you use public key/funds ethically?" Model asked himself in his recorded argument before deciding that a general statement and experimental indications would make it acceptable.

The charge happened on Sepolia, a separate network where developers practice Ethereum applications before launching them. Its tokens only pay for testing and have no link to Ether traded on the Ethereum mainnet.