Is a domain with one letter added or missing a look-alike?

What does a one-letter change look like?

Typo-squatting is a technique by which a threat actor registers domain names that have very similar spelling to and can be easily confused with a legitimate domain address.

Take yourfirm.example. A look-alike might be yourfirrm.example with a second r, yourfim.example with the r gone, or yuorfirm.example with two letters swapped round.

The Cyber Centre notes that typo names exploit typing errors, so people are not always aware they are on the wrong website.

Why does a typo name matter?

typo squatting: threat actors register domain names that are common misspellings of well-known websites, exploiting typing errors so that potential victims are not always aware that they are on the wrong website

A typo name catches two kinds of mistake. A client who mistypes your address can land on a page you do not control, and a client who reads quickly can trust an email sent from it.

The Cyber Centre says such a domain can then deliver malware and collect personal or other sensitive information.

What can I do about typo names?

The new domain can then deliver malware and acquire personally identifiable or other sensitive information.

1. Type your own domain the ways a hurried client might, and note each version.
2. Check which of those versions are registered, and by whom.
3. Register the most likely ones yourself and redirect them to your real site.
4. Tell staff to check the sender's full address on any request about money.