Vladivostok is a city in Russia.
Richard Frampton founded Sojourn Enterprises, a transport multinational with a space tourism division, that in reality was a cover for some of the Ten Rings activities, and located its headquarters in Vladivostok.
One of Frampton's terrorist acts for the Ten Rings was to acquire Hammer Industries's version of Stark Industries Jericho missile. He tasked the mercenary only known as Sofia to retrieve it, killing Russian arms dealer Mikhail Fjodorov and at least three S.H.I.E.L.D. agents in the process, travelling to to Vladivostok to hand the technology to Frampton.
When S.H.I.E.L.D. agent Phil Coulson discovered that Sofia's employer was the billionaire Richard Frampton, Agent Natasha Romanoff infiltrated Sojourn Enterprises headquarters in Vladivostok. There she discovered that he has made a Jericho missile that would explode near the border between Russia and North Korea, greatly destabilising the world peace.