Article Summary:
Spear phishing is a targeted email attack using personalized information to deceive specific individuals or organizations into revealing sensitive data or installing malicious software on their systems.
Unlike broad campaigns, spear phishing employs social engineering and reconnaissance to craft highly convincing messages, making these sophisticated threats much harder for traditional security filters to detect.
Organizations can prevent spear phishing by implementing Multi-Factor Authentication (MFA), using advanced email security solutions, and providing consistent employee training to recognize evolving social engineering tactics.
What is spear phishing?
While phishing is a broad term for attacks that aim to trick a victim into sharing sensitive information, spear phishing is a phishing attack that goes after a single target, which can be an individual, organization, or business.
Spear phishing attacks are particularly effective because the attacker can use information about the victim, oftentimes public information found online, to create a convincing ruse.
Spear phishing vs. 'bulk' phishing
The majority of phishing attacks are not directly targeted. Usually, phishing messages are sent in bulk to as many people as possible, and the attackers hope some small percentage fall for the ruse. This is the cheapest and fastest way to execute phishing attacks. Attackers may incorporate some degree of automation and personalization, especially using AI, but extra customization for a single person or organization is not part of a typical bulk phishing campaign.
The research and personalization that goes into spear phishing takes more effort (and often more money) than an ordinary phishing attack. For this reason spear phishing attacks are rarer by comparison. But, they have a very high rate of success. And when successful, they cause much more damage to their targets.
What social engineering tactics are used in spear phishing?
Spear phishers use tactics common to many types of social engineering attacks in order to manipulate their victims. These include:
Introducing a time limit so that the victim feels they have to act quickly without taking the time to think the request through
Using emotional appeals, such as including information about negative consequences if the recipient does not comply with the fake request
Creating a convincing story, also known as "pretexting"
Including directly relevant details: addressing the recipient by name, sending the email from someone at the recipient's place of employment, including real details about the recipient's life, and so on
What other tactics do spear phishing attacks use?
Beyond personalization, there are several steps attackers often take to make their spear phishing attacks more effective.
Domain and email spoofing: Attackers may imitate email addresses and website URLs to make their scams more convincing.
Account takeover: Instead of faking the sender's email address, an attacker may first gain access to a trusted party's email account and send the spear phishing email from there.
Generative AI: Attackers can use large language models (LLMs) to create or proofread their messages, or to research their targets.
What do spear phishing attacks look like?
A common spear phishing tactic is for the attacker to pose as someone in a position of authority, because people are much more likely to respond to an authority figure.
Here is an example:
Joe is an executive assistant to a CEO named Mary. One day when Mary is on vacation abroad, Joe gets an urgent email from her. The email states that her luggage and phone have been stolen. She says she has no money or passport and needs him to send over her PayPal credentials ASAP so that she can book a hotel and buy a flight home. Joe might see this harrowing message from his employer and immediately send over the requested information.
This sort of "I'm in trouble and need money" request from a superior is a common spear phishing script. The attacker could be spoofing Mary's email, as well as sending the email to dozens of different combinations of Joe's name and initials in hopes of finding the correct one. The attacker may also have learned about Mary's vacation plans by following her on Twitter. Combining all of these tools, the attacker can devise a very convincing con.
A notable real-life example of this happened in 2016, when an attacker posed as the CEO of Snapchat and was able to convince an employee to hand over confidential payroll information.
Spear phishing attacks can also leverage information from data breaches. Another example:
Steve buys a computer at a major online retailer, but a few weeks later the retailer has a data breach. Although sensitive data like credit card numbers and passwords were hash-protected, customer email addresses and order histories were leaked.
A few days later, Steve gets an email from the manufacturer of his new computer announcing that his model is being recalled, and providing a link to receive a refund. The link takes Steve to a fake version of the manufacturer's website and provides a form for Steve to enter his credit card number for the refund. The attacker used some fairly harmless data to gain Steve's confidence and trick him into handing over his financial information.
What is the difference between spear phishing and whaling?
Whaling is a spear phishing attack that targets a very high-profile victim, usually a top executive at a company or a celebrity. Whaling attacks tend to be more sophisticated, and in many cases attackers will first carry out spear phishing attacks on smaller targets, such as employees of the "whale," in order to gain access to their ultimate victim.
For example:
While on vacation, Mary the CEO gets an email or call from someone she knows on her IT team letting her know that they are enduring a cyber attack and requesting access to her work computer and her accounts to ensure that company data can be secured. It is possible that an attacker compromised her IT team in order to gain Mary's trust, in hopes of convincing her to hand over her credentials.
How to protect against spear phishing and whaling
Since spear phishing involves social engineering, there are no foolproof ways to protect against these kinds of attacks. However, a number of precautions can be taken to prevent and mitigate attempts at spear phishing. These include:
Never share financial information, passwords, or any other sensitive data over phone, chat, or email.
Do not click on links in emails, even if they appear to be from a trusted source. Copying and pasting or hand-typing the URL can help protect from cross-site scripting attacks.
Enable 2-factor authentication on all important accounts, so that stolen login credentials are not enough.
Enable Zero Trust security policies to ensure that an intruder does not have open access to a network.