General Indications of Intrusion consist of which of the following?

• A. System Intrusions
• B. File System Intrusions
• C. Repeated Probes
• D. All of the Above

Answer: (D)

Indications that an intrusion is occurring come from signs across different parts of a system. A defender looks for system intrusions, which are unauthorized access or privilege escalation on a host; file system intrusions, where critical files or directories are accessed or tampered with; and repeated probes, which signal ongoing reconnaissance, scans, or repeated failed login attempts. Because intrusion activity can appear in multiple forms, all three types together cover the range of ways attackers reveal themselves. That’s why all of the above is the best answer—each category represents a valid indicator, and they often occur in combination.