BitFinex Hack

Reported loss $332K
Bitcoin
Access Control

What happened

On May 22, 2015, Bitfinex reported that its hot-wallet keys might have been compromised and more than 1,500 BTC were stolen. The exchange said most deposits were held elsewhere in multisignature wallets, replaced hot-wallet and deposit addresses, and said it would absorb the loss.

How it happened

  1. Bitfinex reported a suspected compromise of keys used by its hot wallet.
  2. More than 1,500 BTC were transferred out of the affected hot wallet.
  3. Bitfinex said it held most deposits in separate multisignature wallets.
  4. The exchange replaced the affected hot-wallet and deposit addresses while investigating; the opened updates do not establish the initial key-compromise path.

Protocol details

Classification CeFi / Key Compromise
Protocol Type CEX
Protocol links Website @bitfinex

Evidence

Understand the attack patterns

Compare incidents →
Access Control Attacks

Same attack technique

Browse all hacks →
Ethereum Upbit $51.2M lost Bitcoin Binance $41.7M lost Ethereum Bithumb $19.2M lost Bitcoin Bitfinex $72.0M lost

Build your security review skills

Work through hands-on labs covering real exploit mechanics, review techniques, and defensive patterns.

Start Free Trial Explore attack classes