Three codes were hidden in the HTML source of the RESISTANCE WIN #DARKXMCURE CHALLENGE post on the Investigate Ingress blog.

[1] ggb16ivgivzg674su

[2] qg3oy6xc28db7m

[3] xp351tsohw75dap

Code #1

Observations

Passcode format is there, remember to apply the same method to the keyword

Code #2

Observations

16 characters with the right amount of numbers for a valid passcode

Code #3

Observations

Passcode format is there in reverse, go through you usual cipher routine