Which of the following is MOST effective in detecting such an intrusion?

A system administrator recently informed the IS auditor about the occurrence of several unsuccessful intrusion attempts from outside the organization.

Which of the following is MOST effective in detecting such an intrusion?
A . Periodically reviewing log files
B . Configuring the router as a firewall
C . Using smart cards with one-time passwords
D . Installing biometrics-based authentication

View Answer

Answer: A

Explanation:

The most effective way to detect an intrusion attempt is to periodically review log files, which record the activities and events on a system or network. Log files can provide evidence of unauthorized access attempts, malicious activities, or system errors. Configuring the router as a firewall, using smart cards with one-time passwords, and installing biometrics-based authentication are preventive controls that can reduce the likelihood of an intrusion, but they do not detect it.

References: ISACA CISA Review Manual 27th Edition, page 301