Kautilya's Arthashastra 7.9.45

7.9.45

vijigīṣor amitraṃ yan mitram antardhitāṃ gatam /
upakāre 'niviṣṭaṃ vāśaktaṃ vānupakāri tat //

that friend who is inimical to the conqueror or who is equally friendly to the conquerors enemy is a harmful friend, whether he is giving help or is capable of helping;