Microids is calling their game an Extended Reality Experience, and it will encompass multiple websites, centering around the characters from Still Life, along with some created specifically for the ARG. The story will evolve through various media as players follow hints provided by the alternate reality itself, and the marketing materials surrounding the game.
Clues are to begin appearing on the network of ingame websites soon. Keep an eye on the Still Life website (and ARGN) for further developments.
[EDIT: An apparent trailhead has been found. Check out Lombartech.com.]