Wallet swapping is the replacement of one cryptocurrency address with another so that a payment is redirected to the attacker. The user may still see a valid-looking wallet string, but the funds are sent to a different destination when they copy, paste, or submit the address. Because cryptocurrency transfers are usually irreversible, a single successful swap can cause direct financial loss.
This technique is common in browser-side attacks, where malicious JavaScript changes donation or checkout addresses on the page before the user confirms payment. It can also appear in clipboard hijacking malware, phishing pages, or compromised third-party scripts. Defenses include checking the full address before sending, using integrity controls for web scripts, minimizing trusted dependencies, and monitoring for unexpected changes to payment destinations. In security terms, wallet swapping is a subtle form of content tampering that targets trust in the browser and the payment workflow.