Homoglyph Attack Explained With Tutorial

What is a homograph attack?

A homograph attack is a method of deception wherein a threat actor leverages on the similarities of character scripts to create and register phony domains of existing ones to fool users and lure them into visiting. This attack has some known aliases: homoglyph attack, script spoofing, and homograph domain name spoofing. Characters—i.e., letters and numbers—that look alike are called homoglyphsor homographs, thus the name of the attack. Examples of such are the Latin small letter O (U+006F) and the Digit zero (U+0030). Hypothetically, one might register bl00mberg.com or g00gle.com and get away with it. But in this day and age, such simple character swaps could be easily detected.

In an internationalized domain name (IDN) homograph attack, a threat actor creates and registers one or several fake domains using at least one look-alike character from a different language. Again, hypothetically, one might register gοοgle.com, but not before swapping the Latin small letter O (U+006F) with the Greek small letter Omicron (U+03BF).