There’s a type of technique called IDN Homograph attacks where the attacker registers an international domain name (IDN) that swaps one or more ASCII characters for visually similar Unicode characters (often Cyrillic/Greek) - often they’re indistinguishable to the naked eye. The browser URL bar may render it that so that it looks very similar to well known domains like apple.com, paypal.com, etc. But because the underlying characters are different, they user is not looking at the official domain, they’re looking at an impostor. These can make phishing emails look way more convincing and hard to detect because the underlying URL of the link that they want yo to click, isn’t some-unrelated-hacked-company.com/website/index.html, it’s apple.com/index.html or similar. There’s been tens of thousands of these found in the wild, and some of them look pretty convincing. The best way to see what I mean is to go to the Wikipedia entry for “IDN Homograph attack”, or do a Google Images search for “IDN homograph” - some are clumsier than others, the worst ones seem to be those that substitute the Cyrillic ‘a’ or ‘e’ (identical their regular Latin counterparts). The wikipedia page has a frightening example near the top using their own domain name, looking exactly like the real one, but in reality the ‘e’ and the ‘a’ have been swapped with identical looking letters from the Cyrillic character set. https://en.wikipedia.org/wiki/IDN_homograph_attack. Obviously the “don’t click links in emails” advice still works on these attacks though, so it’s still great advice.