Here is an example of a recent Russian event promotion spam:
Here is the English translation:
Figure 1. Russian-language spam promotion
Look closely at the phone numbers at the bottom: Some digits are not written as numbers but instead as letters. Spammers have replaced the numerical digits with look-alike Russian/English characters in the phone number, a technique to avoid spam-detection we will look at below.
To begin, what follows are a few examples of how spammers have employed this method during the past few years. First, here is a simple set of contact phone numbers listed below:
Then, spammers change the phone number by inserting some random symbols between the numbers:
Eventually spammers become more sophisticated and begin to replace numbers with look-alike Russian or English alphabets. Here is a list of characters which resemble numbers in both Russian and English languages: