It was narrated from Sa'eed bin Zaid bin 'Amr bin Nufail that the Prophet (ﷺ) said:
"Whoever is killed defending his property, he is a martyr." (ES)
English reference (ES): Vol. 3, Book 20, Hadith 2580 (ES)
Arabic reference (ES): Book 20, Hadith 2678 (ES)