Having an evil influence; harmful or malevolent.

अस्वास्थ्यकर

English Usage: The story's antagonist was a malefic force that wreaked havoc on the town.

Hindi Usage: कहानी का प्रतिकूल पात्र एक अस्वास्थ्यकर शक्ति थी जिसने शहर पर आतंक मचाया।

Causing harm or evil.

हानिकारक

English Usage: Her malefic intentions were evident in every plot she devised against him.

Hindi Usage: उसके हानिकारक इरादे हर साजिश में स्पष्ट थे जो उसने उसके खिलाफ बनाई।