Ann, a user, states that her machine has been behaving erratically over the past week. She has experienced slowness and input lag and found text files that appear to contain pieces of her emails or online conversations with coworkers. The technician runs a standard virus scan but detects nothing.
Which of the following types of malware has infected the machine?
A. Ransomware
B. Rootkit
C. Backdoor
D. Keylogger