How much was lost in the Taylor hack?

The Taylor hack resulted in $1.6M in losses on May 21, 2018.

What attack technique was used in the Taylor exploit?

The Taylor 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.

Taylor Hack

TOTAL LOST $1.6M

Medium May 21, 2018 Access Control

Affected Chain 2018 Incident surface

Recovered - No recovery reported

All-Time Rank #706 By amount stolen

Protocol Type Exploit/Access control Target category

Incident Overview

Taylor has been hacked for 2,578 ETH (about $1.5 million) as well as some of its TAY tokens.

The hacker's address:

https://etherscan.io/address/0xf243209d…5f1053

According to a Medium blog post the company published, what truly happened isn’t yet clear, although several indicators point them towards a group of hackers that hacked another project dubbed CypheriumChain for more than 17,000 ETH (about $9.8 million).

The hacker(s), according to Taylor, collected its funds from multiple sources in a single wallet, before transferring them to a larger one:

https://etherscan.io/tx/0x878b3b29…4c83e8

After the theft, the organization’s team managed to identify an attempt to dump its TAY tokens on the decentralized cryptocurrency exchange IDEX:

https://etherscan.io/address/0xf243209d…5f1053#tokentxns

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

Incident Report

Protocol / Project Taylor

Date of Incident May 21, 2018

Attack Technique Access Control

Classification CeFi

Primary Source View Post-Mortem #1 View Post-Mortem #2

Protocol Information

Protocol Type Exploit/Access control

Affected Token TAY

Official Website smarttaylor.io/

Protocol Twitter/X @smarttaylorapp

Team Anonymous

Source Code Unverified

Market Context at Time of Hack

Protocol Links

GitHub Reddit

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 Taylor'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 Taylor, these are the critical security checks that could have prevented this incident (May 2018).

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://www.ccn.com/1-5-million-cryptocurrency-trading-platform-…
02
Source 2 https://medium.com/smarttaylor/this-is-a-dark-day-for-taylor-ded…

Threat Assessment

Severity Level

MEDIUM

Attack Vector Access Control
Root Cause CeFi
Year 2018

Learn to Prevent the Next Taylor

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