Often bundled in "crack" or "keygen" folders within pirated Adobe software distributions.
“Portable” versions of Acrobat with xf-mccs6 are even more dangerous – they often run without UAC prompts, hiding malicious activity. xf-mccs6.exe adobe acrobat
Some versions may create "DirectInput" objects commonly used by spyware to capture what you type. Often bundled in "crack" or "keygen" folders within