Try uploading any cpu miner to virustotal, you'll see it'll get flagged as a virus.
I tried and virustotal reports different values for cpuminer and for kingminer.
This is report of CPUminer:
Avast Win32:Crypt-OSW [Trj]
ESET-NOD32 a variant of Win64/BitCoinMiner.E
GData Archive.Trojan.Agent.FR0O8G 20130820
Ikarus Win32.Crypt
McAfee Artemis!BB84DA99E36A
Norman Suspicious_Gen4.ELNSF
Panda Suspicious file
Symantec WS.Reputation.1
TrendMicro-HouseCall TROJ_GEN.F47V0715
VIPRE Trojan.Win32.Generic!BT
This is report of KINGminer:
Antiy-AVL RiskTool/Win32.BitCoinMiner.gen 20130821
Avast Win32:BitCoinMiner-CA [Trj] 20130821
ESET-NOD32 a variant of Win32/BitCoinMiner.K 20130821
Ikarus Win32.SuspectCrc
Kaspersky not-a-virus:HEUR:RiskTool.Win32.BitCoinMiner.heur
McAfee Artemis!8C81AB18352F
Panda Suspicious file
Symantec WS.Reputation.1
TrendMicro HKTL_BITMINE.SML 20130821
TrendMicro-HouseCall TROJ_GEN.F47V0821
Different report on cpuminer doesn't make me confident that kingminer is legit (without included trojan/virus).
I know there is a chance of false-positive and I certainly hope it is false-positive.