An electronic lockbox including a key bin having an embedded insert. The insert is embedded during a die cast process. The insert enhances the attack resistance of the lockbox from hammering, chiseling, and drilling attacks. The insert includes “3D features” that help with the casting process and attack resistance, including at least one through-hole, at least one slot, and at least one ridge. A housing portion is constructed over multiple drawing stages to increase its hardness and strength, thereby increasing resistance to prying attacks.