Explore the techniques of backdooring Microsoft Office documents using secret master keys in this 30-minute conference talk from BSidesLV 2015. Presented by Shigeo Mitsunari and Yoshinori Takesako, delve into the intricacies of exploiting vulnerabilities in MS Office applications to create hidden access points. Learn about the concept of secret master keys and their potential for compromising document security. Gain insights into the methods used by cybersecurity professionals to identify and mitigate these threats. Understand the implications of such backdoors for organizational security and discover best practices for protecting sensitive information stored in MS Office files.