What was found
(AIRCRAFT NOT GROUNDED) DIRTY SOCK ODOR REPORTED BY FORWARD FLIGHT ATTENDANTS. FORWARD FA'S REPORT SMELL OCCURED DURING DECENT. BOTH PACKS WERE BEING SUPPLIED BY ENGINE BLEED AIR DURIONG THAT TIME / WHILE ATTEMPTING TO PERFORM LEVEL 3 TC 21-000-003, EVIDENCE OF OIL LEAKAGE FOUND ON APU INTAKE PLENUM, INTAKE SCREEN AND APU INTAKE PLENUM SEAL. REMOVED AND REPLACED APU REF W/O 518101 NR'S 00005 AND 00006. THIS CLOSES MDDR# 210108, PLACARDS REMOVED.