The program is correctly identified as a keylogger, as its specific function is to log user keystrokes. The proposed countermeasures are the most appropriate and comprehensive for this scenario.
1. Employ intrusion detection systems (IDS): A Host-Based IDS (HIDS) is particularly effective as it can monitor a system for suspicious activities, such as the installation of unauthorized software, unexpected network connections, or file modifications characteristic of a keylogger.
2. Regularly update the system software: Keyloggers are often installed by exploiting known vulnerabilities in operating systems or applications. A robust patch management program that ensures timely updates is a fundamental preventative measure to close these security gaps and prevent the initial compromise.

A. "Trojan" describes a delivery mechanism for malware, not the payload's specific function of logging keystrokes. "Keylogger" is the more precise term.
B. While a keylogger is a form of spyware, "keylogger" is more specific. The suggested countermeasures are insufficient on their own to prevent the installation.
D. Maintaining backups is a crucial recovery control after an incident, but it does not prevent the attack from occurring again, which is the core of the question. ---

1. National Institute of Standards and Technology (NIST) Special Publication 800-83 Revision 1

Guide to Malware Incident Prevention and Handling for Desktops and Laptops.

Page 2-5

Section 2.3.2 (Spyware): Defines keyloggers as a type of spyware that "captures keystrokes on a compromised computer

" confirming the program's identification.

Page 3-2

Section 3.1.2 (Patch Management): States that organizations must have a patch management process to ensure software is updated

which is a primary defense against malware exploiting vulnerabilities.

2. National Institute of Standards and Technology (NIST) Special Publication 800-94

Guide to Intrusion Detection and Prevention Systems (IDPS).

Page 2-4

Section 2.2.2 (Host-Based IDPS): Explains that a Host-Based IDS (HIDS) "monitors the characteristics of a single host and the events occurring within that host for suspicious activity

" which is a direct method for detecting the installation and operation of malware like a keylogger.

3. Kurose

J. F.

& Ross

K. W. (2017). Computer Networking: A Top-Down Approach (7th ed.). Pearson.

Chapter 8.3

"Malware": This chapter discusses various malware types

including keyloggers. It also outlines defense mechanisms

emphasizing the importance of keeping systems patched ("keep your operating system and applications up-to-date") and using intrusion detection systems to identify infections.