malicious
adj.adj. intending to hurt or upset someone on purpose. You use this to describe people or actions that are mean and unkind.
adj. characterised by a desire to cause harm, pain, or distress to another person. Often describes intent or specific actions rather than a permanent personality trait.
He sent a malicious email to his boss.
The company's website was taken down by a malicious software attack that locked all their files.
While the initial comment seemed like a harmless joke, the subsequent spread of malicious rumors suggested a coordinated effort to damage her professional reputation.
From Middle English malicious, from Old French malicios, from Latin malitiōsus, from malitia (“malice”), from malus (“bad”). Displaced native Middle English ivelwilled and ivelwilly (“malicious”), related to Old English yfelwillende (literally “evil-willing”). By surface analysis, malice + -ious.
Typically precedes the noun it modifies; frequently collocates with 'intent', 'gossip', or 'software'.