You are the administrator for a network. An employee comes to you and says that they were checking their email and something strange happened. They were navigating their Inbox when they came to an…

You are the administrator for a network. An employee comes to you and says that they were checking their email and something strange happened. They were navigating their Inbox when they came to an email that opened in the preview pane. When this happened, they saw a brief popup and their hard drive light began flashing. Based on this information, which type of attack has most likely taken place?