A senior employee received a suspicious email from another executive requesting an urgent wire transfer. Which of the following types of attacks is likely occurring?

Spear phishing is a targeted phishing attack directed at a specific individual using personalized or organizational details to appear credible. The attacker specifically selected this senior employee and crafted the email to reference a known executive, making it far more convincing than a generic phishing attempt. This specificity - targeting one person with tailored content - is the defining characteristic of spear phishing.

Business email compromise refers to attacks where a legitimate business email account is actually hijacked or spoofed as part of a broader financial fraud scheme, which is a more narrowly defined crime category rather than a phishing technique classification.

Vishing uses voice calls or voicemail as the attack medium, not email, so it does not apply to this scenario.

Whaling specifically designates attacks where the victim is a high-profile C-suite executive such as a CEO or CFO - the question identifies a 'senior employee' as the target, which does not necessarily meet the C-level threshold that defines whaling.