var backframe = app.activeWindow.activePage.rectangles.add({geometricBounds:[-3, -3, app.activeDocument.documentPreferences.pageHeight +3, app.activeDocument.documentPreferences.pageWidth +3]}); 

var doc    = app.activeDocument, 
    sd     = app.layoutWindows.firstItem().activeSpread, 
    gb     = [], 
    old_ro = doc.viewPreferences.rulerOrigin; 
          
doc.viewPreferences.rulerOrigin = RulerOrigin.SPREAD_ORIGIN; 
gb = [ 
      sd.pages.firstItem().bounds[0],  
      sd.pages.firstItem().bounds[1], 
      sd.pages.lastItem().bounds[2],  
      sd.pages.lastItem().bounds[3] 
   ]; 
    
sd.pages.firstItem().rectangles.add( 
      { 
         geometricBounds: gb, 
         strokeWeight    : '0.5 pt' 
      } 
   ); 
 
doc.viewPreferences.rulerOrigin = old_ro;