An exploit on the staking platform of the DeFi protocol Ankr led to an excessive minting of the aBNBc token in the early trading hours of 2 December.
Ankr’s liquid staking smart contract allows users to receive aBNBc in return for depositing their BNB coins to the liquid staking smart contract.
What led to the exploit?
Lookonchain reports that the exploiter stole the key to Ankr Deployer, minted 10 trillion aBNBc, and sent it to himself. Using the stolen key, he transferred 1.125 BNB to his address as a gas fee and then began to dump aBNBc.
ABNBc tokens were exchanged for USDC and BNB on PancakeSwap by the exploiter. The BNB tokens were deposited into Tornado Cash and the USDC tokens were cross-chained to Ethereum and swapped.
ABNBc liquidity pools were significantly reduced by PancakeSwap’s huge ABNBc swap at the decentralized exchange (DEX).
As a result of the dumping of aBNBc, its price plummeted within hours. In the last 24 hours, the token’s price has fallen by 99.5% according to CoinMarketCap. Within the same period, trading volume increased by 14,182.19%, indicating a severe ongoing distribution of aBNBc.
The Ankr exploit affected only the aBNBc, but other derivatives of the BNB coin obtained via BNB staking have seen huge drops.
Lookonchain discovered that a trader could profit from the exploit by dumping 183,885 aBNBc with 10 BNB and depositing the same into Helio Money as collateral for a loan of 16 million HAY. He then sold the remaining 16 million HAY for 15.5 million BUSD.
BNB was not unaffected
BNB was worth $289.37 at the time of publication. On the previous day, its price decreased by 3%, according to information from CoinMarketCap. Additionally, due to a price/volume divergence, its trading volume increased by 26% during that time.
A 4-hour chart for Binance Coin showed that the price was clearly oversold. Relative Strength Index (RSI) reading of 38 contrasted with the Money Flow Index (MFI) reading of 25.