Companies grow through mergers and acquisitions. Marketing teams promote new products. New products spawn new web domains. As brand names, URLs, and cloud IT infrastructure proliferate, so does an organization’s vulnerability to impersonation attacks.

Impersonation attacks are a fast-growing form of cybercrime where attackers impersonate contacts or organizations to steal data, credentials, or money. In this article, we’ll explore what these attacks are, the most common types, and how to stop impersonation attacks before they impact your brand and customers.

What is an impersonation attack?

An impersonation attack occurs when cybercriminals pretend to be trusted individuals, companies, or systems to deceive users and gain access to sensitive data.

For example, a bad actor might create a website that mimics your brand’s login page, then email employees a link to it. Once employees enter their credentials, the attacker gains access to internal systems. Armed with the stolen credentials, the attacker can then take over employee accounts to use them in business email compromise attacks, infect company networks with malware, and create other mischief.

Impersonation attack types

Impersonation attacks come in various forms, often tailored to exploit trust in digital communications or brand recognition. Here are some of the most common types of impersonation attack.

Phishing

Phishing is one of the most widespread impersonation attack types, and it’s often the entry point for more complex breaches. In this attack, cybercriminals impersonate legitimate individuals or organizations to trick victims into clicking malicious links or downloading malware, usually with the goal of gaining access to sensitive information and systems.

• Email impersonation involves attackers spoofing a company’s domain or using a similar-looking one to send emails that appear authentic. These emails often include familiar branding and signatures to make them look convincing.
• Executive impersonation (also called CEO fraud) targets employees by posing as high-level executives requesting urgent actions, like transferring funds or sharing important internal documents. Attackers will usually attempt to convey urgency in these emails to pressure recipients into acting immediately, before they have a chance to verify authenticity.

Both of these phishing techniques rely on trust in familiar names or brands, making brand impersonation a critical enabler of these attacks.

Account takeovers

An account takeover (ATO) is a type of attack whereby a malicious actor gains unauthorized access to a legitimate user’s account, most often through stolen login credentials or malware. Once inside, the attacker can impersonate the user to carry out further attacks internally or externally.

Attackers can use compromised employee accounts to send emails from within the company’s domain, which makes phishing messages nearly impossible to detect. This kind of brand impersonation is particularly dangerous because it leverages legitimate access and infrastructure, bypassing many standard security filters.

Cousin domains

Cousin domains (also known as lookalike or typosquatting domains) are slightly altered versions of legitimate web addresses. Attackers register these deceptive domains to trick users into thinking they’re interacting with a trusted brand.

Some ways of altering legitimate domains include:

• Replacing characters (e.g. g00gle.com instead of google.com)
• Adding hyphens or extra words (e.g. company-login.com)
• Using different top-level domains (e.g. .net instead of .com)

These domains are often used in phishing emails and fake login pages. Because they appear extremely similar to real company URLs, users are more likely to trust them — especially if attackers also design the sites using familiar branding.

Man-in-the-Middle attacks

In a Man-in-the-Middle (MitM) attack, a cybercriminal secretly intercepts and alters communication between two parties. Often, attackers pose as a legitimate website or service during the interaction, which is where brand impersonation comes in.

For example, an attacker might host a fake login page on a cousin domain, which relays login credentials to the attacker while simultaneously passing them on to the real site. This keeps the victim (and the legitimate site) completely unaware of the compromise. This real-time impersonation allows attackers to steal data without disrupting the user experience.

MitM attacks that involve impersonated brands are especially dangerous because they exploit the trust users place in secure-looking interfaces and recognizable web elements like HTTPS or login portals.

Security vulnerabilities across industries

To get a sense of the scope of the problem, in 2021 our team analyzed thousands of online assets across industries like telecommunications, pharma, and healthcare. The findings were concerning:

• Telecom: 8 issues per 100 assets
• Pharma: 50 issues per 100 assets
• Healthcare: 114 issues per 100 assets

Although it’s clearly worse in some industries than others, the problem of neglected online assets ripe for exploitation by bad actors is nevertheless prevalent across industries and only growing worse.

How to prevent impersonation attacks

Preventing impersonation attacks requires a proactive, multi-layered approach that combines technology, employee awareness, and continuous monitoring. Here are five essential strategies to minimize exploitable vulnerabilities and reduce your organization’s risk.

1. Continuously monitor your digital footprint

The first step in stopping impersonation attacks is knowing what you have online. Many attacks exploit forgotten or misconfigured assets like old landing pages, unused domains or staging sites. External Attack Surface Management (EASM) tools help with this by continuously scanning and mapping your organization’s digital footprint.

An EASM can identify abandoned websites, exposed interfaces, expired security certificates, and potential entry points for attackers. With automated alerts and actionable insights, EASM makes it easier to shut down risky assets before they can be used in impersonation campaigns.

2. Implement email authentication protocols (DMARC, SPF, DKIM)

One of the most effective ways to defend against email impersonation is by enforcing proper email authentication. Protocols like Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and Domain-based Message Authentication, Reporting & Conformance (DMARC) work together to verify that emails sent from your domain are legitimate.

• SPF ensures that only approved mail servers can send emails on your behalf.
• DKIM uses encryption to confirm that the message was not altered during transit.
• DMARC builds on SPF and DKIM to instruct receiving mail servers how to handle unauthorized messages, including blocking or quarantining them.

When configured correctly, these protocols reduce the likelihood that attackers can spoof your email domain in phishing campaigns.

3. Educate employees on phishing and executive impersonation

Brand impersonation attacks often involve social engineering and take advantage of human trust. That’s why it’s vital to make sure all employees are well educated on how these attacks work, and able to spot the signs.

Carry out regular training sessions on things like phishing awareness, including how to spot suspicious emails, lookalike URLs, and apparently “urgent” requests that mimic high-level executives or trusted vendors. Make sure to emphasize the importance of verifying unusual or urgent requests — especially those involving payments, credentials, or sensitive data — through secondary channels like phone calls.

4. Protect user accounts with strong authentication

Account takeovers, a common tactic in impersonation attacks, are often enabled by weak or reused passwords. To combat this, implement strong password policies and multi-factor authentication (MFA) across all systems and services.

MFA in particular is a vital element of a layered security strategy. It adds a second layer of verification (like a one-time passcode in an authenticator app) which makes it much harder for attackers to gain access, even if credentials are compromised through phishing or data breaches.

5. Utilize threat intelligence to detect credential leaks

Even the most secure organizations can be affected by credential leaks from third-party breaches or dark web activity. Integrating threat intelligence into your security strategy allows you to detect stolen credentials and impersonation attempts in real time.

Solutions like Outpost24’s Cyber Threat Intelligence modules, now integrated into our EASM solution, monitor data leaks, black market chatter, and stolen account listings to alert you before attackers strike. This insight allows for a timely response and credential resets, reducing the window of exposure.

Reduce brand impersonation threats with EASM

Outpost24’s EASM solution (previously Sweepatic) enables online asset and brand monitoring to reduce threats. In addition to inventorying online assets and identifying problems such as expired security certificates and stranded domains and websites, Outpost24’s EASM integrates four Digital Risk Protection modules to supply users with automated threat intelligence data.

The Digital Risk Protection modules in Outpost24’s EASM Platform include:

• Credentials: Find actionable intelligence around leaked, stolen, and sold user credentials. We locate them in real time on the open, deep, and dark web, along with information about relevant malware used to steal the information. Outpost24’s sinkholes, honeypots, crawlers, and sensors are continuously searching for your stolen credentials from leaks, on forums, and in real-time from targeted malware. This helps eliminate serious attack vectors and fraudulent actions in minutes rather than weeks or months.
• Dark Web: Boost your awareness of what’s going on in the underground. Get visibility over malicious activities targeting your organization and proactively prevent future attacks. Gain an advantage by putting an eye on the enemy camp: become better informed about criminals targeting your organization; proactively prepare countermeasures.
• Social Media: Monitor and check your organization’s digital footprint across Web 2.0 repositories, including blogs, forums, websites, and social networks. Find websites not authorized to use your brands and assets claiming partnership affiliation assets and more, so you can take proactive steps to shut them down.
• Data Leakage: Discover if your organization’s sensitive documents and source code has been leaked on the internet, deep web or P2P networks, intentionally or not, such as with shared internal documents with poorly-secured file sharing providers.

Together, these modules enhance an organization’s ability to detect and respond to brand impersonation threats at every level, from fake domains and spoofed social media accounts to stolen credentials circulating on the dark web. By providing real-time visibility and automated alerts, Outpost24’s EASM platform empowers security teams to take swift action against impersonation attempts before they escalate into larger breaches.

Interested to get a comprehensive view of your attack surface risks and reduce the threat of brand impersonation? Book your free attack surface analysis here.