Poly Network
HackedInfrastructure · born 2020 · ✝ 2021
A $600M cross-chain hack where the thief gave it all back.
Poly Network was a cross-chain interoperability protocol. An attacker exploited a contract flaw to steal over $600M across three chains, then returned nearly all of it after public negotiation.
- Peak
- ~$600M+ stolen (mostly returned)
- Cause
- Hacked
- Year of death
- 2021
☠️ Cause of death
A vulnerability in the cross-chain contract let the attacker reassign the keeper role and authorize withdrawals across Ethereum, BSC, and Polygon.
📓 Lessons left behind
- —Privileged contract roles are prime attack targets.
- —On-chain funds are traceable, which can pressure attackers to return them.
- —Even returned-fund hacks expose deep protocol flaws.
🌱 The idea that survived
Traceability as deterrent
Demonstrated that public ledgers make laundering hard, sometimes forcing attackers to return funds.
#bridge#exploit#interoperability