In Bamidbar 22:5 "...Bilaam the son of Beor..." I can't remember where I may have seen it, that Laban (brother of Rachel) had a son named Beor. Could this be the same Beor as mentioned in Parsha Balak?
Targum pseudo-Jonathan (Numbers 22:5) writes:
לבן הארמי הוא בלעם
The Talmud Bavli (Sanhedrin 105a) writes:
הוא בעור הוא כושן רשעתיים הוא לבן הארמי
The Zohar (Vayishlach) writes:
ולבן הארמי...אבוי דבעור הוה ובעור אבוי דבלעם
So Bil'am is either Lavan, Lavan's son, or Lavan's grandson, depending which Midrash you want to go with. (Or he's just a guy named Bil'am, and you don't want to go with any of these Midrashim.)
Rashi in Sanhedrin 105a and the Midrash Tanchuma say that there is a connection between Bilaam and Lavan, and that they might even be the same person.
Rashi teaches us in Sanhedrin that Bilaam thought that Yaakov Avinu made Lavan poor by robbing him, so therefore Bilaam had to curse Bnei Yisrael, proving that they are related.
Additionally, they both desired money, and characteristics do often run in the family.