Obfuscating IP Addresses as Hostnames
https://isc.sans.edu/diary/Obfuscating%20IP%20Addresses%20as%20Hostnames/33280
Microsoft Paint and Photos Embed Server-Issued GUIDs as Invisible Watermarks in Locally-Generated Images
https://xusheng.dev/posts/reversing/mspaint_invisible_watermark/main/
FTP Banners The New Dead Drop Resolver Delivering Novel RATs
https://socradar.io/blog/ftp-banners-new-dead-drop-resolver-rats/
My Upcoming Classes
https://www.sans.org/profiles/dr-johannes-ullrich