GMBL.COMPUTER Hack

TOTAL LOST $815K
Low Referral Claims Logic Exploit / Other arbitrum

Summarize with AI

ChatGPT Perplexity Claude Grok
Affected Chain arbitrum Incident surface
Recovered $384K 47.1% returned
All-Time Rank #876 By amount stolen
Protocol Type Exploit/Other Target category

Incident Overview

Quick Summary

GMBL Computer, a DeFi Gambling Protocol on Arbitrum, suffered a referral system exploit, resulting in the loss of 768,196 $USD worth 471.33 ETH.

Details of the Exploit

GMBL Computer is a DeFi Gambling Protocol running on the Arbitrum chain. On September 5, 2023, the project's referral system was exploited. The attacker took advantage of a vulnerability that allowed them to place "Ghost" bets on a game, which were registered as losses, and thus enabled the claiming of 5% of these "Ghost" bet losses.

The attacker placed massive "Ghost" bets with one account that was referred by another account, allowing the second account to claim over 8 million $GMBL in referrals before the exploit was stopped. The stolen funds were swapped for ETH and sent to another EOA. Out of the stolen 471.33 ETH, 235.5 ETH was later returned.

Block Data Reference

Attacker Address:

https://arbiscan.io/address/0x2d6f1b2c…acbd41

Funds Holder as of Sep 15, 2023:

https://arbiscan.io/address/0x2D6F1B2C…acbD41

Malicious Transactions:

https://arbiscan.io/tx/0x339cc90e…ed8608

https://arbiscan.io/tx/0xc8dbe61c…d75e8b

Funds Returning Transaction:

https://arbiscan.io/tx/0xa020be40…c25685

Proposal of Returning Funds:

https://arbiscan.io/tx/0xfb1b2254…bd8ea7

Incident Report

Protocol / Project GMBL.COMPUTER
Date of Incident
Affected Chain(s) arbitrum
Attack Technique Referral Claims Logic Exploit / Other
Classification Protocol Logic / Other
Primary Source View Post-Mortem

Protocol Information

Protocol Type Exploit/Other
Affected Token GMBL Computer CHiP
Official Website www.gmbl.computer/
Protocol Twitter/X @gmblcomputer
Team Anonymous
Source Code Verified On-Chain

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.

Technical Knowledge Deep understanding of referral claims logic exploit / other and Solidity and EVM internals
Capital Required Seed capital to cover gas and initial position setup
On-Chain Access Ability to interact with arbitrum smart contracts and deploy a custom exploit contract
Protocol Analysis Identification of the exploitable vulnerability in GMBL.COMPUTER's contract logic - root cause: protocol logic / other
Execution Speed Precise transaction ordering and timing to exploit the vulnerability within a single atomic block
Obfuscation Plan A strategy to launder and move stolen funds - typically through mixers, cross-chain bridges, or decentralized DEX swaps to resist tracing

What Auditors Should Check

Could this have been caught in audit? Likely — with a thorough Referral Claims Logic Exploit / Other audit checklist and test coverage

If you're auditing a protocol with similar architecture to GMBL.COMPUTER, these are the critical security checks that could have prevented this incident (September 2023).

  • Verify all logic paths related to Referral Claims Logic Exploit / Other are guarded by proper access controls and input validation
  • 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.

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Funds Recovery

47.1%

Recovered

$384K

Net Loss

431135

Sources & References

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