An information management system creates a modified representation of backup files in a backup copy on restore to overcome the difficulties and challenges imposed by the legal and administrative requirements on the handling of personally information without making changes to the backup copy. In an example, a restore modification component searches backup data files as they are restored from a backup copy but before the restored data files are written into the primary storage system. When the restore modification component identifies a backup data file with a record that matches search criteria defined in the modification repository, the restore modification component replaces one or more of the restored data field values in the record with replacement data values obtained from the modification repository according to respective replacement rules. In this way, the information management system can create a modified representation of the backup copy data without modifying the backup copy.