As firmware threats are becoming more prevalent, security companies are starting to provide UEFI firmware scanners to detect malicious firmware implants. These scanners first acquire a firmware image inside a SPI flash memory on hardware then parse and scan the image with known signatures. Every software-based firmware acquisition on Intel platforms has a risk of being intercepted by SMM rootkits. This risk has been pointed out by security researchers for years. However, there has been no publicly-available implementation and no one has demonstrated the concept practically. In this presentation, I'll explain about the firmware acquisition MitM attack PoC that I implemented to assess the risk correctly. I'll also show that the PoC can hide known bootkit components against both open and closed source firmware security tools. I believe that the findings from this research will be helpful for better firmware scanner implementations in the future. The PoC will be published after the presentation.