You are a security analyst at a financial firm. An employee receives an instant message from a sender claiming to be from the IT department, asking them to click a link and enter their login credentials to update their account. The employee fell for the attack due to the message's specific nature, including correct names of an IT Department employee and the name of the target employee. What type of threat is most likely being attempted?
Spear Phishing
Vishing
Whaling
Smishing