Portable Document Format (PDF) files, while widely used, can pose significant security risks as highlighted in Jens Müller's presentation at Black Hat USA 2020. The complexity and ubiquity of PDFs make them attractive targets for attackers, with potential threats including denial of service attacks through infinite loops or deflate bombs, which can crash systems by overloading them. Additionally, PDFs can hide more severe vulnerabilities such as informational disclosure, where malicious files can leak users' IP addresses or allow unauthorized access to local files, potentially leading to privacy breaches. A particularly severe vulnerability involves code execution through logical bugs rather than buffer overflows, although this only affects a few PDF readers. Müller's research underscores the importance of caution when dealing with PDFs from unknown sources and suggests that web browsers' built-in PDF viewers generally offer the least security risk. The findings emphasize the need for continuous security vigilance and the role of ethical hackers in identifying emerging threats, as demonstrated by Detectify's efforts to provide cutting-edge security research and solutions.