a zombie apocalypse story written in a few months and a lot of effort

this is about what would happen is there was a spill of a biohazard toxic that turned the living to the dead to attack each other

fell

As a disturbing virus has spread across the world, a few groups of teens make their way through the remnants of their homes, attempting to survive and find their friends and family. Weekly Updates/Complete

The nights are getting longer and colder, and Nat's finally caught a break. They want nothing except peace and time to heal their wounds, without hellish creatures screaming for blood. But, when their new group's crops get ruined, true priorities are revealed, and Nat's scars are ripped open again as they're forced to retrace their old grounds in a desperate search for supplies. All the while, signs of their past still keep them closed-off from the one person who tries to take a chance on them. ------ total word count: 18,816 an entry for WattpadZombies Z-Fic Novella contest

what is this world?