This morning, there was an on-chain development worth noting — the Balancer attacker has taken new action again. He used permit() authorization to transfer approximately 19.5 million stS from the address previously frozen by Sonic (0xf19…fae2), worth about 3 million dollars. The assets have now been converted into WBTC and ETH. The new address is 0x0e9c…44D5.

There is a key technical detail here: this freeze only takes effect at the native chain layer, so it can only lock the native tokens themselves and has no effect on other ERC20 tokens. As a derivative token, stS exploited this loophole — the attacker used the authorization mechanism to bypass the freeze restrictions. It seems that for on-chain security, simply freezing addresses is not enough.