Security incident · 2026-06-25
Polymarket International
According to the public DefiLlama incident dataset, Polymarket International (Polygon) suffered a security incident on 2026-06-25, with about $3.0M reported lost.
| Date | 2026-06-25 |
|---|---|
| Reported loss | $3.0M |
| Chain | Polygon |
| Target type | DeFi Protocol |
| Technique class | Frontend & Infrastructure |
| Technique | Frontend Compromise |
| Bridge incident | No |
| Within 2026 | #62 by loss that year, 0.1% of all reported losses that year |
How this kind of attack works
The website, domain or hosting was hijacked, and users signed transactions that sent funds to the attacker from a page that looked normal.
Would a pre-payment check have helped
When a frontend or domain is hijacked the payee address is freshly generated and on no list, but the hijacked host is often already in public phishing feeds, so endpoint screening catches part of this class.
Other incidents with the same technique
- Mixin Network2023-09-23 · $200.0M
- Badger DAO2021-12-02 · $120.0M
- Atomic Wallet2023-06-03 · $100.0M
- NiceHash2017-12-08 · $64.0M
- SwissBorg2025-09-09 · $41.5M
- IRA Financial / Gemini2022-02-12 · $36.0M