Overview#IDN homograph attack (Internationalized Domain Name) is a Phishing attack where a malicious party may deceive computer users about what remote system they are communicating with, by exploiting the fact that many different characters look alike.
For example, a regular user of example.com may be lured to click a link where the Latin A is replaced with the Cyrillic A.
Unicode incorporates numerous writing systems, and, for a number of reasons, similar-looking characters such as Greek Ο, Latin O, and Cyrillic О were not assigned the same code. Their incorrect or malicious usage is a possibility for security attacks.
The registration of homographic domain names is akin to typosquatting, in that both forms of attacks use a similar-looking name to a more established domain to fool a user. The major difference is that in typosquatting the perpetrator relies on natural human typos, while in homograph spoofing the perpetrator intentionally deceives the End-User with visually indistinguishable names.