Adobe Flash zero-day flaw appeared in the Angler exploit kit. Researchers at Websense found that the exploit code for the vulnerability is hidden inside a Flash file that is in turn wrapped in an SWF file. The goal of the attackers in using this technique is to hide their true intentions and their exploit code from security systems for as long as possible. Flash vulnerabilities are highly valuable for attackers, as the software is deployed on hundreds of millions of machines around the world and users aren t always on the ball about updating it.
Source: https://threatpost.com/analysis-of-flash-zero-day-shows-layers-of-obfuscation/110674/