Additionally, this hash can be looked up directly in the database:
SELECT MF.CONTENTHASH, MC.CONTEXTLEVEL, MC.INSTANCEID
FROM MDL_FILES MF, MDL_CONTEXT MC
WHERE MF.CONTENTHASH = '39d4158ce815d93b944b307f73ba3d21a1e12596'
AND MF.CONTEXTID = MC.ID
This query will show everywhere this file is linked. Depending on the contextlevel; 30 being User, 40 being coursecategory, 50 being course, 70 being module; the Instance ID then refers to UserID, Course Category ID, Course ID or Module ID respectively.