amoral
artful
conscienceless
corrupt
corrupted
crafty
criminal
crooked
cunning
dark
deceitful
devious
dishonest
dishonorable
disingenuous
doubtful
dubious
evasive
evil
faithless
false
felonious
fishy
fraudulent
ill-got
ill-gotten
immoral
improper
inaccurate
indirect
inexact
insidious
knavish
mercenary
not kosher
perfidious
questionable
roguish
rotten
scheming
shady
shameless
shifty
sinister
slippery
sly
sneaky
stick-at-nothing
suspicious
treacherous
ambitious
arrogant
enterprising
greedy
heartless
lawless
malicious
merciless
ruthless
unprincipled
vindictive
scrupulous
ethical
upstanding