About:
Spam arrives in people's inboxes not just in English but in a variety of languages, such as Chinese, French, Russian, Spanish et cetera. One special kind of these spam varieties is a short, text-only Russian message—except they are not written in traditional Cyrillic character sets, but rather encoded in UTF-8.
These messages are normally straight to the point with a call-to-action (CTA) being a phone number in Russia for people to call, followed by their set prices for sending bulk mail advertisements within Moscow as well as delivering to all regions within the Russian Federation.
This kind of email arrives from all types of bot-controlled/compromised networks, from many different geographical regions around the world, but mostly outside of Russian networks.
Of course, the spammers are most interested in the "pay" part; they cycle through a variety of phone numbers and employ numerous tricks to obfuscate the phone number itself, such as substituting numeric one (1) with capital I or lowercase L. The other unique and often-employed trick is to replace numeric 3 and 4 with two Russian letters З and Ч respectively.
Users at risk are all email users with a decent email client and/or webmail interface, especially those who understand Russian. These clients don't have to be the "latest and greatest" technology, since Unicode support has long been enabled in email delivery.
This threat does not pose a great risk to users outside of Russia, but is a great example of how spam is considered a socially-acceptable marketing technique within the Russian market.