BlocksInform
The Decentralised Finance Protocol Cow Swap (Defi) underwent an intelligent contract operation, leading to a loss of about 551 nbp ($181,600).
Reports indicate, the attacker has added a portfolio address as a cow swap "resolver" and invoked a transaction to approve dai to swapguard transfers before moving the assets to other addresses.
A Settlement Contract Exploit
Blockchain surveyor MevRefund first noticed the attack in the early hours of today. The maximal extractable value (MEV) searcher tweeted that CoW Swap’s funds were being moved, adding that the protocol’s SwapGuard feature had been granted allowance and allowed anyone to make “arbitrary function calls.”
Within an hour, blockchain security firm PeckShield revealed that CoW Swap’s GPv2Settlement contract was tricked ten days ago, approving SwapGuard for DAI spending.
At the time of operation, the attacker has just activated the swap guard to transfer dai out of the gpv2settlement settlement agreement.
In further detail, blockchain security platform blocksec revealed that the attacker had added a portfolio address as a protocol resolver through the multiig, hence, Ability to approve deals. As the transfer of case was approved from the settlement agreement, the operator was also able to approve the transfers to arbitrary addresses.
“A lesson learned. An arbitrary call interface contract should not have compensation, 0x55a37a2e5e5973510ac9d9c723aec213fa161919. made the mistake and approved the maximum value of DAI to SwapGuard, which is the root cause of the attack,” BlockSec said.
Over $181k Moved to Tornado Cash
Tokens transferred to the exploiter’s address include BNB, USDT, USDC, and ETH. To date, approximately 551 ETNs valued at more than $181,000 have been transferred to a crypto blender sanctioned by OFAC Tornado Cash.
CoW Swap urged users not to worry, as the stolen funds were CoW Protocol’s accumulated fees from the past week. The platform stated that the problem has been alleviated and is currently being investigated.
The Cow Protocol is the latest challenge platform to endure at the hands of bold hackers this month. CryptoPotato reported last week that Orion Protocol and BonqDAO were hacked, leading to the loss of $3 million and $10 million, respectively.
