Before the apocalypse, Socks had left home and joined a Motorcycle Club known as the Sisterhood. She was only in the club for a short time before the world went to shit, however, the apocalypse opened up a new prosperous chapter for the club. The club took over a stretch of highway in the Midwest and soon after that a small town just off the highway. They would mess with and rob anyone passing through and above all just have the times of their lives causing chaos. Overtime they created enemies and lost sisters to either war or just moving on to something new. The group slowly turned from the Sisterhood to the Chaos Crew, known for their destruction and madness. They heard rumors, many rumors, that a small country overseas had a stockpile of explosives, treasure, and even nukes... with those they could rule over the whole country! Or even the world! They rode for the coast, finding a running ship with a crew and taking them hostage, forcing them to sail across the ocean to their riches. They would end up finally after long at sea, pillaging anything along the way, they would finally make landing... in the wrong country. The Chaos Crew left the ship and it's crew to move more inland, eventually discovering they had been in Russia the whole time and having to make their way on foot to Chernarus.
That's the bare basics, something something they're idiots.