What happened
Leaked admin key led to a malicious ProxyAdmin upgrade.
Transaction-level mechanics
Public post-incident disclosures do not include full transaction calldata or execution traces for this incident.
TODO: Add exact Safe transaction hash, decoded actions, and the on-chain state changes once verified primary sources are available. For now, the attack vector summary above is derived from public reporting.
What independent decoding / hash verification / config scanning would have caught
Not a Safe-signing failure, but implementation/upgrade monitoring of the pattern this tool checks would have flagged the ProxyAdmin change instantly.
Verdict
Could have helped partially