What is spear phishing?

Spear phishing attempts to deceive victims into clicking malicious links or downloading malware-infected attachments. When this happens, they can extract login credentials and other sensitive information or deliver ransomware and other harmful malware variants.

How does spear phishing work?

Spear phishing works by tricking victims into taking risky actions. The most common way to achieve this aim is by assuming the persona of a contact the victim knows and trusts. For example, phishers might impersonate a trusted IT vendor or a globally known financial services provider.

Spear phishing is a sophisticated technique that starts with carefully researching targets. Phishers gather intelligence about the victim's work activities and private life. They acquire information via open-source resources (such as LinkedIn) or by purchasing identity profiles on the dark web.

Researching targets allows criminals to deploy social engineering techniques that exploit human nature for criminal purposes. Attackers combine intelligence and manipulative language that convinces targets to carry out specific actions.

Spear phishing campaigns often use urgent language and tight deadlines to encourage action. For instance, spear phishing attackers may use scenarios like imminent tax payments. They may send fake security notifications that appear legitimate. Or they may imitate routine requests from colleagues, whatever it takes to prompt action.

Spear phishing emails or SMS messages include a call to action that connects the target with the attack vector. For example, emails may direct employees to a fake password reset portal or a shipping data form requesting financial details.

In other cases, spear phishing attacks send malware via infected PDF files, spreadsheets, or documents containing malicious scripts. Clicking the attachment executes embedded malware, launching data theft or ransomware attacks.

Understanding the difference between spear phishing, phishing, and whaling

There are many types of phishing attacks. Although spear phishing is one of the most dangerous (and common) types, security teams need to guard against all varieties. Understanding the difference between spear phishing, standard phishing, and whaling attacks is critically important.

Spear phishing vs standard phishing attacks

Simple phishing attacks send general emails or other content to many targets. Phishing emails are not generally personalized for each recipient (although automated attacks can add basic information to make emails seem more legitimate).

Phishers use bulk emails to cast their net wide. They do not mind that 99 percent of recipients ignore their messages. Thanks to the low cost of sending bulk emails, a few successful click-throughs are sufficient to generate a profit.

Spear phishing attacks

Spear phishing attacks differ from standard phishing because they use social engineering techniques to create personalized content. Criminals use personal details to build trust and encourage hazardous actions.

Advanced spear phishing attackers also leverage AI to reduce the cost of attacks. Phishers use LLMs to research targets and generate emails with click-through rates that match or better human-written content.

Attackers often send personalized spear phishing emails to many individuals in the same organization. If attackers strategically compromise a group of accounts at the same organization, this can lead to data breaches and secondary network attacks.

Spear phishing vs whaling attacks

Whaling is a specialist form of spear phishing that targets high-ranking officers and executives. Whaling attacks focus on privileged accounts with access to sensitive information and the authority to issue directives to employees or corporate partners.

Whalers extensively research their targets, often months before sending emails. Criminals may build relationships with their victims via social media or direct emails and phone calls. The more attackers know, the easier it is to fool and manipulate high-value targets.

Whaling attacks are labor-intensive and more expensive than spear phishing. Spear phishing scams are easier to scale and can be executed more quickly. However, successful whaling attacks are extremely lucrative. As a result, executives are always appealing targets for phishing collectives.

Examples of spear phishing attacks

Criminals continuously assess targets and trade information via Telegram channels or dark web marketplaces. As these examples show, every organization is vulnerable to spear phishing attempts.

Fake vendor invoices

These spear phishing attacks imitate trusted vendors the victim's company uses. Attackers know that the target routinely approves invoices from the vendor. They gamble that the target will interact with phishers as if they were legitimate contacts.

Emails include a notification that late invoice payment will incur penalties or service interruptions. Malicious links embedded in the notification email direct the employee to a payment portal, which harvests their financial details and sends them to the phishing collective.

IT support scams

Other spear phishing scams exploit our dependence on specialist IT support partners. Phishers imitate the IT support teams at regular technology partners. They send emails notifying employees about technical difficulties or imminent password expiry.

Recipients click through to fake websites to resolve the IT issue. They then enter their credentials, believing they are accessing legitimate IT services. AI chatbots may also imitate support teams, giving IT scams more credibility.

Internal scams

Spear phishing attacks do not always emulate external partners or trusted brands. Phishers can also assume the persona of colleagues, making it vital to screen every email arriving at business email inboxes.

Some internal spear phishing scams exploit the self interest of employees. For example, attackers may imitate Human Resources officers and inform an employee that they qualify for a substantial bonus. When targets click through to claim their bonus, a fake payroll site extracts their credentials.

HR teams are useful to phishers because they offer ways to manipulate emotions. Employees will regularly click through to discover information about their vacation entitlement or bonus terms. These spear phishing emails are often hard to detect and prevent via staff training.

CEO fraud

This type of business email compromise (BEC) mirrors whaling attacks by pretending to be the company CEO. Spear phishing attacks send content to junior employees, instructing them to carry out risky actions. For example, attackers might order finance officers to make a one-off payment to a fake support company.

CEO fraud is effective because senior executives possess authority. Junior staff are often reluctant to question their instructions. As a result, even emails containing red flags such as "confidential payments" pass undetected.

As you can probably see, spear phishing is a flexible technique. We could extend the list above further with fraudulent charity requests, fake job offers, spoofed IRS domains, bogus legal threats, and many other methods. Companies need prevention methods that cover all of these manipulative scams.

How to prevent spear phishing

Spear phishing can lead to data breaches, malware infection, credential theft, and regulatory penalties. This makes prevention critically important. However, countering phishers is not easy, especially if attackers use social engineering and well-crafted content.

However, businesses can manage cyber-attack risks by following best practices to prevent spear phishing attacks:

Add download protection to your toolkit

Spear phishing attacks often use malicious attachments or drive-by downloads delivered via malicious links. NordLayer's download and web protection tools mitigate both risks.

Download protection tools help prevent spear phishing attacks by screening downloads before self-executing on network devices. Web protection employs DNS filtering to block known attack sites, while deep packet inspection (DPI) blocks unauthorized apps.

Use multi-factor authentication to mitigate credential theft

Multi-factor authentication adds an insurance policy if phishers steal user credentials. Authentication tools request unique one-time credentials via tokens or SMS messages. Only users with the one-time code can access the network. User names and passwords are not sufficient.

MFA also cuts the risk of account takeovers. Phishers find it harder to control internal accounts and send spear phishing emails from internal email addresses.

Security awareness training

Training is the heart of a robust phishing prevention strategy. Workforces that understand spear phishing risks are well-placed to analyze emails and detect attacks before they succeed.

Security awareness training conveys the importance of verifying contacts before sending confidential information or clicking attachments. Staff should also know the red flags of spear phishing emails (such as misspelled content, spoofed sender addresses, and unusually urgent language).

Use phishing simulations to build knowledge in workplace scenarios and create confidential tools to report suspected spear phishing emails.

Manage access to sensitive information with Zero Trust controls

Spear phishing attacks often expose network assets by allowing attackers to move laterally within compromised networks. Phishers with access to privileged accounts can explore databases and extract information for sale or use in further attacks.

Zero Trust network architecture (ZTNA) provides a solution. Assign users with minimal privileges needed to carry out their professional duties. Access to resources is blocked by default unless the user passes verification tests. This dramatically reduces the scope for phishers to exploit compromised accounts.

Implement email security tools

Email signatures verify the authenticity of senders and recipients, assuring security teams that phishers have not infiltrated the chain of communication.

Use DomainKeys Identified Mail (DKIM) to ensure emails are not altered in transit, and the Sender Policy Framework (SPF) to guard against spoofed domain names. Combine both with Domain-based Message Authentication, Reporting, and Conformance (DMARC) to report failed checks and flag suspected phishing emails.

Monitor public information about corporate activities

In some cases, attackers purchase profiles from stolen datasets. However, most spear phishing attacks rely on open-source intelligence about targets. Companies can reduce their attack surface by limiting the amount of public information about employees and business operations.

Enforce strict policies that prevent the use of business accounts to post information about private lives. Remind employees that criminals exploit details about individuals to craft phishing content, particularly when researching executive-level targets.

Threat intelligence platforms can help. These tools search dark web forums and other sources to track mentions of companies or individuals. This intelligence may provide early warning about compromised accounts.

Raise awareness to prevent spear phishing attacks

Spear phishing deceives victims, leading them to download files or visit websites they would normally avoid. This manipulative cyberattack is common, accessible to most phishing groups, and very damaging when successful. Effective prevention measures are crucial.

Build awareness with regular staff training. Use email signatures, download protection, and DNS filtering to detect phishing attempts. And if phishers succeed, multi-factor authentication and Zero Trust controls protect provide a second line of defense.