Which of the following should be monitored by threat intelligence researchers who search for leaked credentials?

A customer has reported that an organization's website displayed an image of a smiley (ace rather than the expected web page for a short time two days earlier. A security analyst reviews log tries and sees the following around the lime of the incident:

Which of the following is MOST likely occurring?

During an investigation, a security manager receives notification from local authorities mat company proprietary data was found on a former employees home computer, The former employee's corporate workstation has since been repurposed, and the data on the hard drive has been overwritten Which of the following would BEST provide the security manager with enough details to determine when the data was removed from the company network?

A user is concerned that a web application will not be able to handle unexpected or random input without crashing. Which of the following BEST describes the type of testing the user should perform?

After a hardware incident, an unplanned emergency maintenance activity was conducted to rectify the issue.
Multiple alerts were generated on the SIEM during this period of time. Which of the following BEST explains what happened?