Smuggle Bus
From Just Solve the File Format Problem
Smuggle Bus by Jason Caminsky is a PowerShell script that hides files in other files.
It takes the file(s) you want to hide, puts them in an encrypted zip, appends that to the end of a benign "mask" file, then takes the last X bytes of the mask file and appends those to the end, thereby "sandwiching" the hidden, encrypted files in the middle. Both the beginning and end of the file look like the mask file. And the necessary information to extract the hidden files are hidden in a special "pocket" in the middle of the file (and you can customize the obfuscation for it to make it nearly impossible for anyone to find that pocket).
There is also an option to extract and launch PowerShell scripts in memory.
