There is a bug in this miner which sends duplicate shares :
2016-10-31 19:33:42 (Thread 124) Suspicious Share rejected (Attack?): {“job”:“13”,“ip”:“x”,“worker”:“xxx”,“difficulty”:15.60970206,“error”:“job not found”}
2016-10-31 19:33:51 (Thread 14) Suspicious Share rejected (Attack?): {“job”:“13”,“ip”:“x”,“worker”:“xxx”,“difficulty”:15.60970206,“error”:“job not found”}
2016-10-31 19:34:03 (Thread 95) Suspicious Share rejected (Attack?): {“job”:“13”,“ip”:“x”,“worker”:“xxx”,“difficulty”:15.60970206,“error”:“job not found”}
Be aware that you get this error when you mine on a pool that actually checks the shares for validity