Looks like they were eradicated completely in the days of Joshua.......
Numbers 13:30:33
30But Caleb quieted the people before Moses and said, “Let us go up at once and occupy it, for we are well able to overcome it.”
31Then the men who had gone up with him said, “We are not able to go up against the people, for they are stronger than we are.”
32So they brought to the people of Israel a bad report of the land that they had spied out, saying,
“The land, through which we have gone to spy it out, is a land that devours its inhabitants, and all the people that we saw in it are of great height. 33A
nd there we saw the Nephilim (the sons of Anak, who come from the Nephilim), and we seemed to ourselves like grasshoppers, and so we seemed to them.”
Joshua 11:21-23
21And Joshua came at that time and cut off the Anakim from the hill country, from Hebron, from Debir, from Anab, and from all the hill country of Judah, and from all the hill country of Israel. Joshua devoted them to destruction with their cities. 22There was none of the Anakim left in the land of the people of Israel. Only in Gaza, in Gath, and in Ashdod did some remain.
23So Joshua took the whole land, according to all that the Lord had spoken to Moses. And Joshua gave it for an inheritance to Israel according to their tribal allotments. And the land had rest from war.
"Anakim(
long-necked), a race of giants, descendants of Arba, (
Joshua 15:13;
21:11) dwelling in the southern part of Canaan, and particularly at Hebron, which from their progenitor received the name of "city of Arba." Anak was the name of the race rather than that of an individual. (
Joshua 14:15) The race appears to have been divided into three tribes or families, bearing the names Sheshai, Ahiman and Talmai. Though the war-like appearance of the Anakim had struck the Israelites with terror in the time of Moses, (
Numbers 13:28;
9:2)
they were nevertheless dispossessed by Joshua, (
Joshua 11:21,22) and their chief city, Hebron, became the possession of Caleb. (
Joshua 15:14;
Judges 1:20)
After this time they vanish from history."
(
Source)