Unbacked rate hikes hit Swell's swETH and rswETH after Railway's key leak

On Oct. 22, security researcher Spreek reported that someone using Swell DAO’s operational hot keys—online keys that sign without human input—raised the exchange rates of its swETH and rswETH liquid staking tokens by about 1% an hour without new ETH backing them; researcher Odysseus counted five hikes. The reports followed Railway’s Oct. 21 disclosure that an intruder may have accessed stored customer secrets, though no link to Swell has been confirmed. Swell said it was investigating suspicious contract activity and that the swETH and rswETH deposit and withdrawal contracts still held their ETH; it paused both on Oct. 23. Spreek reported four malicious upgrade contracts that could take about 2,500 ETH if executed, none of which had run.