Incident Overview
On June 25, 2025, multiple attacks on BNB Chain targeted unidentified, closed-source contracts—likely MEV arbitrage bots—resulting in a combined loss of approximately $2 million. Despite speculation, Venus Protocol was not involved.
Attackers exploited a flaw in the victim contracts’ validation logic, which only checked if the caller was authorized, but failed to restrict what functions could be invoked. This allowed malicious actors to use authorized contracts to directly call sensitive functions and drain assets like vTokens. The attack targeted bots such as printMoney and was executed through a series of crafted calls exploiting poor internal permission handling.
Attack Transaction Tx: 0x7708aaed…131f44
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 MEV Bots, these are the critical security checks that could have prevented this incident (June 2025).
- Verify all logic paths related to 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
Learn to Prevent the Next MEV Bots
The MEV Bots hack is one of many attacks that skilled auditors are trained to detect before deployment. Master real exploit patterns and defense techniques with hands-on Web3 security training.