The Midrash Shochar Tov (22:25) writes
לשלשה חלקים נחלק ממונו של המן. שליש למרדכי ואסתר. ושליש לעמלי תורה. ושליש לבנין בית המקדש - Haman's money was divided into thirds: 1/3 was given to Mordechai and Esther, 1/3 was given to those learning Torah, and 1/3 was given to build the Beis HaMikdash.
Was Haman rewarded for supporting Torah and the Beis HaMikdash? (The Gemara Gittin (57b) says Haman's grandchildren reportedly learned in Bnei Brak - Shmaya V'Avtalyon who taught all of Klal Yisroel - but the Gemara doesn't say that was his reward per se)