Yes. Allah ordered the punishment for theft in the Quran (5:38), which shows that it is a serious sin. Taking another person's property wrongfully in any way is forbidden.
Al ladrón y a la ladrona, cortadles las manos como retribución de lo que han cometido, como castigo ejemplar de Alá. Alá es poderoso, sabio.
This is general information, not a fatwa. For your own situation, ask a qualified scholar.
Questions about halal and haram
Is stealing haram?
Yes. Allah ordered the punishment for theft in the Quran (5:38), which shows that it is a serious sin. Taking another person's property wrongfully in any way is forbidden.