No "indirectly" about it; this is precisely what "satanists" believe. Satanism is in fact merely Catholicism inverted in that it shares all the beliefs of Catholicism but then roots for the other side.
Where satanism and chrstianity are both wrong is in their belief in some sort of "fallen angel adversary" of G-d who runs an "independent" kingdom of evil. While Satan as understood by Judaism most certainly exists, the "satan" of chrstianity (and of satanism) does not.
And yes, I am aware that this teaching is explicitly taught in the "new testament." However, it is not in the Hebrew Bible.
Although, per Christian theology, Satan certainly runs a kingdom of evil, populated by fallen angels, it is not independent. Satan needs permission from God to do anything. The idea of an independent kingdom of evil is a Manichean concept that was condemned as heresy by the Church long ago.
"How art thou fallen from heaven, O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations!
For thou hast said in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north:
I will ascend above the heights of the clouds; I will be like the most High.
Yet thou shalt be brought down to hell, to the sides of the pit."
Can you show me how the Satan of Judaism differs from the Satan of Christianity? I would be very interested in learning that.