What is whaling phishing?

Whaling, or whale phishing, refers to phishing attacks directed specifically at high-profile targets. Whaling attacks involve a large amount of personalization.

Learning Objectives

After reading this article you will be able to:

  • Define whaling
  • Understand how scammers personalize and optimize their whale phishing messages
  • Explain how to prevent whaling attacks

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What is whaling?

Whaling or whale phishing is a type of attack that targets high-level executives, usually over digital channels such as email, text message, or instant message. A form of spear phishing, whaling is highly personalized and typically involves a great deal of research from the scammer. The goal of a whale phishing attack is data, access, or money. Because whaling targets members of the C-suite or other senior leaders, the scammers tend to be after extremely sensitive data, high levels of access, or large amounts of money.

Like other kinds of phishing, whaling involves social engineering in order to get the target to act quickly. The scammers use a number of techniques to conceal their true identities, from domain spoofing to impersonation.

Whaling attacks, though expensive and time-consuming (for the attacker) and therefore more rare, can have a huge negative impact on a business. Organizations need to guard against whaling in addition to their typical phishing defenses, since whaling uses tactics that may bypass ordinary security measures.

What social engineering tactics are used in whaling attacks?

Scammers may go to great lengths to engineer their whaling campaigns. Whaling attacks are worth it from their perspective because they are aiming for a big payout. Some of the main tactics they use:

Including personal details to gain legitimacy: Personalization helps the message seem authentic. Details about the intended victim's job or personal life can come from a variety of sources.

Raising the stakes: Whaling messages may incite the target to take action right away, before some negative consequence happens. To add urgency, whaling attacks often relate to important or highly visible events, such as business mergers, legal inquiries, major financial transactions, or data breaches.

Impersonating a trusted person: Scammers use domain spoofing, fake instant messaging handles, or even SIM-swapped phone numbers to pretend to be someone the target knows. They may imitate the trusted person's writing style, or use deepfakes to imitate their voice or appearance. Whaling attackers can even use the actual account of the trusted person if they have compromised it in a previous account takeover campaign. One common version of this tactic involves the scammer impersonating the CEO and reaching out to HR executives or high-level members of the finance department.

Multiple interactions, not just a single email as in a garden-variety phishing attack. The scammer may aim to get the intended victim's trust over a period of weeks or months. For instance, a scammer pretending to be the CEO of Acme Corp. might send emails to Acme Corp.'s Director of HR from an email address that differs slightly from the real CEO's email, but with legitimate messages so that the Director of HR gets used to responding to such emails. Then, once trust is gained, they make their malicious request.

Inserting message as part of ongoing conversation or transaction: Going one step beyond impersonation, attackers can send messages as part of preexisting threads. This is difficult to pull off but previous successful account takeover attacks can make it possible.

How do whaling attackers personalize their messages?

Scammers have a number of channels available for obtaining the information they need to personalize their messages, making themselves sound familiar to the intended victim.

  • Publicly available information: Whaling targets may be in highly visible roles, which means there can be lots of information about them available to the public. Attackers can use this information to decide whom to target, to plan their attacks, and to personalize the individual messages they send.
  • Social media information: For instance, if a CTO just attended a conference in Las Vegas, Nevada, and posted about it, an attacker could pose as a contact they met at that conference.
  • Research of company hierarchy and functions: Much of a company's hierarchy can be discovered from its website or from social media platforms.
  • Previously compromised data: Collections of personal information, including contact information, are available for purchase on the dark web, or the scammer may have obtained such information from previous attacks.
  • Insider participation (intentional or unintentional): Attackers might use social engineering to manipulate company employees into revealing inside information about a company's structure and workings, or the habits of its leaders. Alternatively, malicious insiders and corporate spies can deliberately communicate this information to the whalers.

How do whale phishing attacks use AI?

  • To generate messages: Large language models (LLMs) make it far easier to create convincing, error-free messages or emails.
  • To imitate trusted parties: AI can help scammers imitate someone's writing style or their voice on the phone.
  • Vibe coding for brand imitation: Fake websites or authentic-looking email design can be built faster than ever with vibe coding.
  • Automation: Part of the process of identifying potential targets, compromising downstream accounts, or other aspects of the whaling lifecycle can be automated using AI.

Whaling vs. business email compromise (BEC)

Whaling attacks share some attributes with business email compromise (BEC) attacks. Like BEC attacks, whaling attacks rely heavily on social engineering, rather than malware or malicious links, so they are more likely to slip through email security filters. But BEC attacks may target low- or mid-level members of an organization, whereas whaling exclusively targets the C-suite or other highly placed, prominent figures. Because attackers expect a bigger payoff, whaling attacks may be even more intricately constructed than typical BEC campaigns, and attackers may be highly persistent.

Whaling can take place over channels other than email as well. In fact, multi-channel attacks have become more common across all kinds of phishing.

How to prevent whaling attacks

Attackers investing enough resources and time into carrying out a whaling attack are likely to make sure their emails pass basic security checks like DMARC, DKIM, and SPF. This is of course not always the case and it is worth using these security checks, but they should not be solely relied upon. Whale phishing attacks also may fail to trip traditional secure email gateways because they usually do not include malicious links or attachments, and attackers may be careful to avoid sending them from known bad IP addresses.

For these reasons, email security filters that analyze sender reputation, message sentiment, and conversation context, along with other attributes, are essential for detecting potential whaling attacks (as with BEC prevention). Unusual requests or messages can be flagged as suspicious and investigated or blocked.

Finally, all employees, contractors, and leaders within an organization should be trained regularly on how to spot potential phishing campaigns, and to check in with the purported sender of an email or a message over another trusted channel before completing major transactions.

Learn how Cloudflare Email Security stops whaling and BEC attacks before they happen.

 

FAQs

What is whaling and whom does it typically target?

Whaling, also known as whale phishing, is a specialized digital attack that focuses on high-level leaders and C-suite executives. Unlike broad phishing attempts, these attacks are highly personalized and involve extensive research to target individuals with significant authority or access.

How does a whaling attack differ from standard business email compromise?

While both methods use social engineering, whaling specifically targets prominent, high-ranking figures within an organization. Because the potential rewards are greater, whaling campaigns are often more persistent and intricately designed than typical BEC attacks, which may target employees at any level.

What are the primary motives behind whaling attacks?

Scammers carry out whaling campaigns to obtain large sums of money, gain entry into secure systems, or steal highly sensitive corporate data.

Which social engineering techniques do attackers use to build trust?

Attackers may interact with a target over weeks or months to establish a sense of legitimacy before making a malicious request. They often use personal details, mimic a specific person's writing style, or even use deepfakes and compromised accounts to appear authentic.

In what ways do scammers use urgency to manipulate their targets?

Whaling messages often raise the stakes by linking their requests to critical events like legal inquiries, company mergers, or data breaches. This pressures the executive to act immediately to avoid a perceived negative consequence.