Appended (8)
'appended' is the definition.
('add' can be a synonym of 'append')
This is all the clue.
(Other definitions for added that I've seen before include "Summed up" , "Totted" , "Appended; totalled" , "Extra" , "Counted up" .)
(Other definitions for attached that I've seen before include "Fastened together, joined to" , "Stuck" , "in a relationship" , "Affixed" , "Connected, associated" .)