137,000 bitcoin in apparently unrelated wallets emptied in two hours, all paying the same fee. Who had the keys?
On 28 December 2020 a silent cluster of weak-random wallets was drained. Years later an OP_RETURN begged a 'whitehat' to talk.
The appearance
Wallets with no shared on-chain history fired at once. Balances fell from ~137,000 BTC to under 200 BTC in two hours. About 9,500 BTC went to a Lubian mining-pool payout address. The rest, roughly 120,000 BTC, went to fresh wallets. Every suspicious spend used the same fee. That is not how humans pay.
Case file sealed
Investigation notes, the reconstruction, and sources sit behind this seal. Open it when you have sat with the raw transaction.
Open the case file
The investigation
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01 The RNG
The addresses were generated with broken randomness — a small keyspace, not a stolen seed phrase typed once. Researchers later clustered them as the largest known family of 'weak random wallets' on mainnet. If you can search a reduced keyspace, you do not need malware on 137,000 machines. You need a scanner and time.
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02 Lubian’s letter
On 3 July 2022 and 25 July 2024, OP_RETURN payloads appeared from some of the same keys: 'MSG from LB. To the whitehat who is saving our asset, you can contact us through [email] to discuss the return of asset and your reward.' LB is read as Lubian.com. 'Saving' is doing a lot of work. Anyone who still holds those private keys can write OP_RETURNs from them, including the original thief.
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03 White-hat or not
A white-hat who seized keys to protect them usually returns coins to a well-known recovery process, or holds them visibly. Four years of silence and a mining-pool deposit are not that process. The more boring read: a hunter who won the RNG race, parked coins, and later someone with leftover keys tried to negotiate.
Reconstruction
A keyspace collapse, not 137,000 separate hacks. Weak random number generation produced addresses whose private keys could be brute-forced. An automated sweeper drained them on 28 December 2020 with identical fees. Lubian — or someone who can still sign for those keys — later tried to open a channel with whoever holds the pile. The coins have not come home in public.
Still open: Which generator produced the weak keys, who ran the 2020 sweep, and whether any coins were returned privately.