How much was lost in the Cdecker hack?

The Cdecker hack resulted in $113K in losses on September 28, 2012.

What attack technique was used in the Cdecker exploit?

The Cdecker exploit utilized Access Control. Understanding this attack vector is critical for smart contract auditors and developers building secure DeFi protocols.

How can developers prevent similar smart contract attacks?

Preventing smart contract hacks requires a combination of secure coding practices, thorough security audits, and understanding common attack vectors like reentrancy, oracle manipulation, and access control flaws. Smart Contract Hacking (SCH) provides hands-on training to help developers and auditors identify and prevent vulnerabilities before deployment.

Cdecker Hack

TOTAL LOST $113K

Low Sep 28, 2012 Access Control

Affected Chain 2012 Incident surface

Recovered - No recovery reported

All-Time Rank #1458 By amount stolen

Protocol Type Exploit/Access control Target category

Incident Overview

A supposedly long-time user of Bitcoin found his personal wallet emptied of a significant amount in late September 2012. Because far more severe personal thefts had occurred in the past, the theft went by without much incident.

This is classified as a Access Control Attacks . Compare similar hacks →

Incident Report

Protocol / Project Cdecker

Date of Incident September 28, 2012

Attack Technique Access Control

Classification Token

Primary Source View Post-Mortem

Protocol Information

Protocol Type Exploit/Access control

Team Anonymous

Source Code Unverified

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 Operational-security tradecraft (phishing, malware, leaked seed phrases, or insider access) to obtain treasury signing authority

Capital Required Minimal capital - only enough to cover gas while draining the compromised accounts

On-Chain Access Valid signing authority over the compromised wallets / multisig signers, allowing direct transfer of funds or stake authorization

Target Reconnaissance Identification of Cdecker's high-value treasury accounts and the authority / multisig structure controlling them

Execution Speed Speed to drain the compromised accounts before the team detects the breach and revokes signing authority or freezes the assets

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 Access Control audit checklist and test coverage

If you're auditing a protocol with similar architecture to Cdecker, these are the critical security checks that could have prevented this incident (September 2012).

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.

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Related Attack Classes

The technique used in this hack maps to these vulnerability classes in our security curriculum:

See all Access Control Attacks examples →

Access Control Attacks

Sources & References

01
Source 1 https://bitcointalk.org/index.php?topic=83794.0#post_cdecker_theft

Threat Assessment

Severity Level

LOW

Attack Vector Access Control
Root Cause Token
Year 2012

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