BTC Guild Hack

TOTAL LOST $58K
Low Other

What happened

When BTCGuild was upgrading the Bitcoind client to 0.8, the mining pool used its original upgrade plan. However, 0.8 is unique in that it reindexes the blockchain. This prompted a temporary state in which the pool was paying out for difficulty-1 shares, as that was the extent of the blockchain parsed.

Sixteen separate thieves subsequently emptied the hot wallet. 47 BTC have been returned to the pool. The pool would on the following day lose even more money thanks to a bug causing its recent upgrade to 0.8 to differ from nodes running 0.7 or lower.

Case & protocol details

Classification Token
Protocol Type Exploit/Other
Official Website btcgold.biz/
Protocol Twitter/X @btcgold1

Evidence & learning

Sources and on-chain records

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