A more thorough explanation:

Definition: Malicious is an adjective that describes something or someone that is intended to cause harm or injury without any just cause or excuse.

Examples:

• A hacker who creates a virus to destroy someone's computer is acting maliciously.
• A person who spreads false rumors about someone else to damage their reputation is acting maliciously.
• A dog that bites someone without provocation is considered to have acted maliciously.

The examples illustrate the definition of malicious by showing actions that are intended to cause harm or injury without any just cause or excuse. In each example, the person or thing is acting with the intention of causing harm, and there is no valid reason for their actions.