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SecurityQuiet 13d · day 14

Binance hot wallet drained of $2.5B after EIP-7702 delegation signatures

Analysis suggests attacker obtained signing capability without possessing the wallet's private key.

newest coverage 13d agosummary written 11d ago3 pieces11 likes & upvotes Hacker NewsMastodon

What to know

  • Binance hot wallet 14 lost $2.5–2.8 billion (167,464 ETH and 63 tokens) on October 29 after fifty EIP-7702 delegations enabled a contract drain.
  • Technical evidence suggests the attacker obtained valid signatures without possessing the wallet's private key, indicating a signing compromise rather than direct key theft.
  • The attack exploited EIP-7702's design: signing services cannot inspect what hashes they sign, and policy engines cannot see the delegation parameters.
  • The attacker practiced the technique on throwaway accounts before targeting Binance, using a carrier address to submit the pre-signed delegations.

Binance Compromised exchange0xQuit Ethereum analyst

How it unfolded 1 development · click the chart to see its coverage posts

Peak 2 pieces in 4h at Oct 30, 11 AM; 3 pieces over 14 days (3 posts) Oct 30, 3 AM — 1 piece · 1 post — Hacker News 1Oct 30, 7 AM — quietOct 30, 11 AM — 2 pieces · 2 posts — Hacker News 1, Mastodon 1Oct 30, 3 PM — quietOct 30, 7 PM — quietOct 30, 11 PM — quietOct 31, 3 AM — quietOct 31, 7 AM — quietOct 31, 11 AM — quietOct 31, 3 PM — quietOct 31, 7 PM — quietOct 31, 11 PM — quietNov 1, 2 AM — quietNov 1, 6 AM — quietNov 1, 10 AM — quietNov 1, 2 PM — quietNov 1, 6 PM — quietNov 1, 10 PM — quietNov 2, 2 AM — quietNov 2, 6 AM — quietNov 2, 10 AM — quietNov 2, 2 PM — quietNov 2, 6 PM — quietNov 2, 10 PM — quietNov 3, 2 AM — quietNov 3, 6 AM — quietNov 3, 10 AM — quietNov 3, 2 PM — quietNov 3, 6 PM — quietNov 3, 10 PM — quietNov 4, 2 AM — quietNov 4, 6 AM — quietNov 4, 10 AM — quietNov 4, 2 PM — quietNov 4, 6 PM — quietNov 4, 10 PM — quietNov 5, 2 AM — quietNov 5, 6 AM — quietNov 5, 10 AM — quietNov 5, 2 PM — quietNov 5, 6 PM — quietNov 5, 10 PM — quietNov 6, 2 AM — quietNov 6, 6 AM — quietNov 6, 10 AM — quietNov 6, 2 PM — quietNov 6, 6 PM — quietNov 6, 10 PM — quietNov 7, 2 AM — quietNov 7, 6 AM — quietNov 7, 10 AM — quietNov 7, 2 PM — quietNov 7, 6 PM — quietNov 7, 10 PM — quietNov 8, 2 AM — quietNov 8, 6 AM — quietNov 8, 10 AM — quietNov 8, 2 PM — quietNov 8, 6 PM — quietNov 8, 10 PM — quietNov 9, 2 AM — quietNov 9, 6 AM — quietNov 9, 10 AM — quietNov 9, 2 PM — quietNov 9, 6 PM — quietNov 9, 10 PM — quietNov 10, 2 AM — quietNov 10, 6 AM — quietNov 10, 10 AM — quietNov 10, 2 PM — quietNov 10, 6 PM — quietNov 10, 10 PM — quietYesterday, 2 AM — quietYesterday, 6 AM — quietYesterday, 10 AM — quietYesterday, 2 PM — quietYesterday, 6 PM — quietYesterday, 10 PM — quietToday, 2 AM — quietToday, 6 AM — quietToday, 10 AM — quietToday, 2 PM — quietToday, 6 PM — quiet 1
Oct 31Nov 1Nov 2Nov 3Nov 4Nov 5Nov 6Nov 7Nov 8Nov 9Nov 10now · 9:09 PM ET
  1. 1

    Technical analysis reveals signing without key possession

    Detailed analysis of the attack mechanism shows the attacker obtained fifty valid signatures for a nonce window (18914775–18914824) without possessing the wallet's private key. The attacker practiced the attack on throwaway accounts before targeting Binance 14, using a carrier address that was empty two days prior. The signing service and policy engine were unable to prevent the attack due to the properties of EIP-7702 authorization.

    “A signing service that is handed 32-byte digests, the hashes it signs without seeing what they hash, cannot tell this one from a transaction hash.”
    — 808bits analysis
  2. background

    0xQuit argues attacker did not hold the wallet's private key — By 21:09 UTC, analyst 0xQuit posted that whoever performed the attack did not hold the wallet's key, because someone with the key would not have needed a second account to carry the signatures on chain.

  3. background

    Contract drains 167,464 ETH from Binance hot wallet — Three minutes and twenty-four seconds after the delegation signatures, the contract empties the wallet in a single call, moving 167,464 ETH, 63 tokens including 1.615 billion USDT to an address that had never received anything before. The total value was between $2.5 and $2.8 billion at explorer prices that evening.

  4. background

    Binance hot wallet signs fifty EIP-7702 delegations — A transaction containing an authorization list of fifty entries signed by Binance hot wallet 14 lands in Ethereum block 26300753. Each entry delegates execution to a contract deployed that afternoon. The transaction moves no ether and calls nothing.