A week after switching on non-Eurocentric character support in Gmail, Google has announced that it's working to get its spam filters working in the new world.
“Scammers can exploit the fact that ဝ, ૦, and ο look nearly identical to the letter o, and by mixing and matching them, they can hoodwink unsuspecting victims”, writes Mark Ritter of Google's spam and abuse team. “Can you imagine the risk of clicking “ShဝppingSite” vs. “ShoppingSite” or “MyBank” vs. “MyBɑnk”?”
(The various characters used here, Ritter notes, are U+101D (the Myanmar letter Wa), U+AE6 (Gujarati digit zero), the Greek small omicron U+03BF and an ASCII “o”.
The Unicode community, Google explains, has put together rules for detecting such obfuscations, called “Restriction Level Detection”.
Using this standard, Gmail should be able to detect attempts at obfuscating a fake link using a look-alike character, with a mail rule stating that “The authenticating domain, envelope From domain, payload From domain, reply-to domain, and sender domain should not violate the highly-restrictive Unicode Security Profile guidelines for international domain names.” ®