Incident Overview
Wintermute's DeFi operations have been exploited for $160m in total according to the company's CEO.
Wintermute is an algorithmic market maker that provides liquidity across CeFi and DeFi exchanges as well as over-the-counter deals. Wintermute's CEO announced on the morning of the 20th of September that its DeFi operations had been hacked, CeFi and OTC services have not been affected. The company claims to be solvent despite $160m in assets taken and further states that 90 different assets were affected. Most of the assets taken were worth under $2,5m and therefore the markets should not be shaken by major sell-offs.
It appears that Wintermute had suffered a brute force private key compromise. The company used Profanity's services for generating vanity addresses. The private keys were generated in such a way that through using enough computing power every possible combination could be tried through until the code was hacked.
Several EOA addresses and two smart contracts have been used to attack the platform.
The attacker gained power over Wintermute's wallet and repeatedly used a privileged function to transfer funds from the Wintermute wallet to his malicious smart contracts which then transferred the funds to the attackers EOA address, where the assets are sitting at the moment.
Attacker EOA address:
https://etherscan.io/address/0xe74b28c2…B84705
Attacker smart contracts:
https://etherscan.io/address/0x00000000…0f9e75
https://etherscan.io/address/0x0248f752…385c26
Transfer transactions:
https://etherscan.io/tx/0xedd31e2a…0e9ec4
https://etherscan.io/tx/0xc253450f…bbe876
Incident Report
Protocol Information
What the Attacker Needed to Succeed
Understanding the prerequisites for this type of attack helps auditors identify protocols that are most at risk and helps developers build better defenses.
What Auditors Should Check
If you're auditing a protocol with similar architecture to Wintermute, these are the critical security checks that could have prevented this incident (September 2022).
- Verify all logic paths related to Private Key Compromised (Brute Force) / Access Control are guarded by proper access controls and input validation - see the Access Control Attacks attack class for patterns
- Review privileged functions (owner, admin, governance) for potential abuse vectors - centralization risks should be documented and bounded with timelocks or multi-sigs
Master these auditing techniques with hands-on labs and real exploit scenarios in the Smart Contract Hacking course.
Free TrialRelated Attack Classes
The technique used in this hack maps to these vulnerability classes in our security curriculum:
Sources & References
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