The ability to monitor computer file systems for unauthorized changes is a powerful administrative tool. Ideally this task could be performed remotely under the direction of the administrator to allow on-demand checking, and use of tailorable reporting and exception policies targeted to adjustable groups of network elements. This paper introduces M-FICA, a Mobile File Integrity and Consistency Analyzer as a prototype to achieve this capability using mobile agents. The M-FICA file tampering detection approach uses MD5 message digests to identify file changes. Two agent types, Initiator and Examiner, are used to perform file integrity tasks. An Initiator travels to client systems, computes a file digest, then stores those digests in a database file located on write-once media. An Examiner agent computes a new digest to compare with the original digests in the database file. Changes in digest values indicate that the file contents have been modified. The design and evaluation results for a prototype developed in the Concordia agent framework are described.