Every time a wallet interacts with a decentralized application, it may be asked to grant that application permission to spend a specific token on the wallet's behalf. Many of these approvals are granted for an unlimited amount by default, since it is more convenient for the app, and many are never revoked once the original interaction is done.
Why an old approval is still a live risk
An old, forgotten approval to a contract that is later compromised or maliciously updated can be used to drain a wallet with no further action from the owner. This is one of the most common mechanisms behind decentralized finance related losses we investigate, and it is dangerous precisely because the approval itself does not expire and requires no further confirmation to be exercised.
A short, repeatable process
- Open a reputable wallet interface or blockchain explorer that includes an approvals management view.
- Review the full list of active approvals, not just recent ones.
- Revoke anything tied to an application you no longer use, recognize, or trust.
- Pay particular attention to any approval set to an unlimited amount.
- Repeat this every few weeks for an actively used wallet, rather than only after something feels wrong.
Reviewing a wallet's active approvals periodically, and revoking anything no longer in active use, closes this attack path with minimal effort. Most major wallet interfaces and blockchain explorers now include a dedicated approvals management view built specifically for this purpose.
This is a preventative habit, not a response to an active incident, but it remains one of the few genuinely effective steps available to any wallet holder without specialist tools.