1. A machine-implemented process for screening data for malware, the process being performed by a computer system having processing circuitry operatively coupled to at least one data store, the process comprising: storing received data in the at least one data store, wherein the received data includes at least: (i) a first and a second protected item of data, each containing contents that are inaccessible without corresponding access credential information, and (ii) first access credential information corresponding to the first protected item of data, the first access credential information having been received separately from the first protected item of data; storing other access credential information in the at least one data store, the other access credential information including at least second access credential information corresponding to the second protected item of data; analyzing the received data to detect the first protected item of data therein based on predetermined protected data item identification criteria; analyzing the received data to detect the first access credential information contained therein based on predetermined access credential identification criteria that includes application of a measure of proximity between information items contained in separately-received portions of the received data and detected protected items of data in the received data; in response to a detection of the first access credential information in the at least one data store, storing the first access credential information in the at least one data store in a grouping arrangement with the other access credential information; in response to a detection of at least one of the first and the second protected item of data, using the corresponding access credential information stored in the grouping arrangement, including the first access credential information and the second access credential information, to facilitate access to the first and the second protected items of data by a malware screening process to extract content from the first and the second protected items of data; and executing the malware screening process to scan the content extracted from the first and the second protected items of data to detect a presence of malware.