Neutron governance takeover (Astroport, Drop) hack — September 2026

An attacker used Neutron's own on-chain governance to take over contracts belonging to protocols deployed on the chain on 22 September 2026. Neutron DAO voters passed proposal 9, titled 'AIATO: AI Agent Takeover. Phase 1: Agent Admin Registration', which contained eleven Update Admin actions. The voting power needed to pass it cost the attacker about $20,199 in NTRN. The contracts, which included infrastructure used by the Astroport exchange and the Drop liquid-staking protocol, were then migrated to malicious code that let their assets be withdrawn. Neutron is a smart-contract chain in the Cosmos ecosystem that had entered what it called a long-term maintenance phase earlier in the year.

Estimates of the loss differ by more than a factor of two. Spaydh, a former Neutron contributor, put the initial impact at roughly $4.4m: about $3m in ATOM, $1.2m in USDC, around $100,000 in DYDX and smaller amounts of wstETH and WETH, and said Neutron's rate limits and the subsequent halt protected more than $1.6m in USDC along with significant amounts of NTRN and ASTRO. The security tracker SlowMist recorded $4.9m at Astroport and $4.4m at Drop, $9.3m in all, and Protos put the initial losses at $9.5m. The itemised $4.4m is recorded as the headline because it is the only account that breaks the loss down; the security firms' totals, which may include assets the halt kept from leaving, are kept as the upper end of the range.

Neutron halted, trapping an estimated $5m of assets on the chain, according to Protos. Part of the stolen ATOM had already been moved to the Cosmos Hub over IBC and was being sold through cross-chain liquidity, so Hub validators halted their own chain at block 33,086,740 on 22 September. They restarted it at 12:00 UTC on 23 September on Gaia v28.3.0, with a one-time state change at the halted height that moved the attacker's remaining balance, 1,227,121 ATOM or about $2.2m, into a 4-of-6 validator multisig. The Cosmos Hub stressed that it was not itself exploited and that no other balance was touched. The swept ATOM is recorded as recovered; it is being held for return and has not yet reached users.

The sweep did not catch everything. Seven blocks after the restart a THORChain refund of 168,990.9 ATOM reached the attacker's address; about six hours later it was moved to Osmosis and sold for roughly 266,841 USDC, according to the analyst Rarma as reported by CryptoSlate. As of 24 September Neutron contributors had prepared a new binary to restore the affected contracts to their previous code and administrators, tighten governance and move the remaining attacker-controlled assets into a validator multisig, with returns to users to follow the restart and a post-mortem promised once the chain is back online.