PYE Hack

TOTAL LOST $2.6M
Medium Other

Summarize with AI

ChatGPT Perplexity Claude Grok
Affected Chain 2022 Incident surface
Recovered - No recovery reported
All-Time Rank #586 By amount stolen
Protocol Type Exploit/Other Target category

Incident Overview

PYE smart contract was exploited in a bunch of transactions. The example transaction:

https://bscscan.com/tx/0x3823a684…7fe2b1

The exploit occurred because of the lack of "k invariant verification" in the swap() routine, meaning that a caller verification was removed in the PYESwapPair. There are suspicions that this was an insider job.

The part of the stolen funds was deposited into the Tornado Cash mixer on the BNB chain, the rest was bridged to Ethereum and deposited into the mixer as well:

https://etherscan.io/address/0x85b86b43…0a92ee

Incident Report

Protocol / Project PYE
Date of Incident
Attack Technique Other
Classification Other
Primary Source View Post-Mortem #1 View Post-Mortem #2

Protocol Information

Protocol Type Exploit/Other
Affected Token PYE
Official Website www.pye.net/
Protocol Twitter/X @PyeEcosystem
Team Anonymous
Source Code Unverified

Market Context at Time of Hack

Token Categories
Memes Ethereum Ecosystem
Protocol Links

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 other and Solidity and EVM internals
Capital Required Seed capital to cover gas and initial position setup
On-Chain Access Ability to interact with smart contracts and deploy a custom exploit contract
Protocol Analysis Identification of the exploitable vulnerability in PYE's contract logic - root cause: 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 Other audit checklist and test coverage

If you're auditing a protocol with similar architecture to PYE, these are the critical security checks that could have prevented this incident (March 2022).

  • Verify all logic paths related to 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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Sources & References

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