Cryptocurrency hackers and exploiters seemingly slowed down for the 2022 holidays as December saw $62.2 million worth of cryptocurrencies stolen, the “lowest monthly figure” of the year, according to CertiK.
The blockchain security company on Dec. 31 tweeted a list of the month's most significant attacks. It highlighted the $15.5 million worth of exit scams as the method that stole the most value over the month, followed by the $7.6 million worth of flash loan-based exploits.
A later tweet on Jan. 1 confirmed that the 23 largest exploits were responsible for around 98.5% of the $62.2 million figure, with the $15 million Helio Protocol incident on Dec. 2 the largest of the month.
The protocol, which manages the stablecoin HAY (HAY), suffered a loss when a trader took advantage of a price discrepancy in Ankr Reward Bearing Staked BNB (aBNBc) to borrow millions worth of HAY.
At the time, the decentralized finance (DeFi) protocol Ankr suffered a separate exploit where an attacker minted 20 trillion aBNBc, causing its price to plummet. The Helio trader quickly deposited aBNBc tokens to borrow 16 million HAY, causing the loan to be significantly undercollateralized, leading to the protocol's loss and a depeg of its stablecoin.
The second largest incident of the month was the $12.9 million exploits of Defrost Finance’s v1 and v2 protocols on Dec. 23, where an attacker carried out a flash loan attack by adding a fake collateral token and a malicious price oracle to liquidate the protocol.
Days after the exploit, the hacker returned the funds stolen from the v1 protocol to an address controlled by Defrost, though funds are yet to have been returned for the v2 hack.
CertiK labeled the exploit an “exit scam” due to the fact an admin key was required to conduct the attack. Defrost denied the allegations to Cointelegraph, claiming the key was compromised.
The December figure is much lower than the month prior, seeing an 89.5% decrease from the $595 million worth of exploits across 36 major incidents CertiK recorded in November, a figure largely skewed by the $477 million hack of crypto exchange FTX.
Overall for 2022, just the largest 10 exploits of the year funneled around $2.1 billion to bad actors, largely on cross-blockchain bridges and DeFi protocols.