What is one characteristic of a bot that poses a security risk?

A characteristic of a bot that poses a security risk is its ability to alter settings on a user's device without permission. This capability can be particularly dangerous because it allows malicious bots to manipulate system configurations, install unauthorized software, or change security settings. Such alterations can lead to vulnerabilities in the system, making it easier for an attacker to exploit these weaknesses for further compromise, data theft, or unauthorized access.

In contrast, the other options do not reflect inherent risks associated with bots. While some bots may perform legitimate tasks, this does not imply a security risk. The capability to improve device performance can be a positive trait if the bot operates as intended. Additionally, functioning only during specific hours of usage does not necessarily indicate a security threat; it may simply reflect the bot's programming or intended use case. Therefore, the ability to make unauthorized changes is what distinctly highlights the threat that certain bots can pose in cybersecurity.