A security operations team was alerted to abnormal DNS activity coming from a user’s machine. The team performed a forensic investigation and discovered a host had been compromised. Malicious code was using DNS as a tunnel to extract data from the client machine, which had been leaked and transferred to an unsecure public Internet site. Which of the following BEST describes the attack?
A. Phishing
B. Pharming
C. Cache poisoning
D. Data exfiltration