200-201 Question 211
Single answerA cybersecurity analyst receives an alert from the SIEM platform regarding unusual outbound traffic from a server. Upon investigating the command line logs, they find repeated instances of a netcat (nc) command being executed to establish connections to an external IP address on port 4444. What is the most likely interpretation of this activity?
- A
The server is running a legitimate backup process.
- B
The server is under a brute force attack.
- C
The server is being used as part of a data exfiltration attempt.
- D
The server is performing a scheduled software update.
Show answer and explanation
Correct answer: C
Explanation
The repeated use of netcat (nc) to establish connections to an unknown external IP address on port 4444 is highly indicative of malicious activity. This behavior aligns with patterns commonly associated with data exfiltration attempts, where attackers use tools like netcat to transfer sensitive data to external systems. Recognizing such activity is crucial for identifying and responding to potential security breaches.
- A. Incorrect.
Backup processes typically involve file transfers to known internal or authorized external destinations, not random external IP addresses over unusual ports like 4444.
- B. Incorrect.
Brute force attacks usually involve repeated login attempts and would show up as authentication failures in logs, not as outbound netcat connections.
- C. Correct.
Netcat (nc) is a versatile tool often used by attackers for data exfiltration, as it can establish direct connections to an external system on arbitrary ports. In this case, the activity suggests potential unauthorized data transfer.
- D. Incorrect.
Scheduled software updates usually connect to trusted vendor servers on standard or well-known ports, rather than an unexpected external IP address on port 4444.