Troubleshooting CPU Spikes - oftpd process

Platform Full Name : FortiAnalyzer-2000B Version : v5.4.6-build1244 180904 (GA)

We're trying to identify the reason why the oftpd process is consuming 700%+ CPU usage.  debug's have been less than helpful.  kill the oftpd process and the CPU usage resumes back to normal.

Any suggestions are appreciated.  Thank you!