bad, evil, immoral, shameful, sinful, unethical, wicked, wrong

blamable, blameworthy, censurable, reprehensible

banned, barred, contraband, criminalized, disallowed, discouraged, forbidden, interdicted, outlawed, prohibited, proscribed

adulterine, bootleg, unauthorized, unlicensed, unsanctioned

under-the-counter, under-the-table

corrupt, unprincipled, unscrupulous, villainous