It’s Halloween weekend—and there is a boogeyman out there. This is no drill. The residents of Northern Virginia are under a terror threat over the next 72 hours as officials warn that an active ISIS cell could launch an attack soon. Authorities have warned folks heading into malls and shopping centers. Reportedly, two ISIS operatives have been tasked with carrying out some attack in a population center. Police presence will be increased in the area (via CBS News):Police in Northern Virginia are on a heightened state of alert as a new law enforcement alert warned of a potential threat against malls and shopping centers located just outside of Washington, D.C. The threat originated with ISIS and is the basis for the alert, sources …