The Clint who tried to infect Hiro in The Black Sun got away, but he left his scroll behind—he didn't reckon on having his arms lopped off—and Hiro dumped it into the tunnel system below the floor, the place where the Graveyard Daemons live. Later, Hiro had a Daemon take the scroll back to his workshop. And anything that is in Hiro's house is, by definition, stored inside his own computer. He doesn't have to jack into the global network in order to access it.