Evolution of macro VBA obfuscation techniques

The widespread use of documents and email across the world, in various company departments (human resources, accounting, legal, etc) in conjunction with macro VBA language available for Office applications, has perpetuated a very efficient attack vector over the years. An attacker simply has to create a fake document with a macro VBA and send it to one of these departments masked as a legitimate document to engineer a potential breach. While security products have updated their detection technologies, so did the obfuscation techniques used in these attacks. This paper focuses on how this obfuscation techniques have evolved in the last decade.