Little horn was perhaps Antiochus IV Epiphanes
John said there were many antichrists even in his day.
And I think Paul said "they are not all Israel who are of Israel"
1 John 4:3And every spirit that confesseth not that Jesus Christ is come in the flesh is not of God: and this is that
spirit of antichrist, whereof ye have heard that it should come; and even now already is it in the world.
1 John 2:18-25 Amplified Bible, Classic Edition (AMPC)
18 [a]Boys (lads), it is the last time (hour, the end of this age). And as you have heard that the antichrist [he who will oppose Christ in the guise of Christ] is coming, even now many antichrists have arisen, which confirms our belief that it is the final (the end) time.
19 They went out from our number, but they did not [really] belong to us; for if they had been of us, they would have remained with us. But [they withdrew] that it might be plain that they all are not of us.
20 But you have been anointed by [you hold a sacred appointment from, you have been given an unction from] the Holy One, and you all know [the Truth] or you know all things.
21 I write to you not because you are ignorant and do not perceive and know the Truth, but because you do perceive and know it, and [know positively] that nothing false (no deception, no lie) is of the Truth.
22 Who is [such a] liar as he who denies that Jesus is the Christ (the Messiah)? He is the antichrist (the antagonist of Christ), who [
habitually] denies and refuses to acknowledge the Father and the Son.
23 No one who [[c]habitually] denies (disowns) the Son [d]even has the Father. Whoever confesses (acknowledges and has) the Son has the Father also.
24 As for you, keep in your hearts what you have heard from the beginning. If what you heard from the first dwells and remains in you, then you will dwell in the Son and in the Father [always].
25 And this is what He Himself has promised us—the life, the eternal [life].