Impersonation attacks in healthcare email communication

Impersonation attacks in email communication are a major cybersecurity risk in healthcare, largely because email is still the primary channel for sharing operational, financial, and sometimes clinical information. As Stephen Ginn notes in the article, Email in healthcare: pros, cons and efficient use, "Email is a major means of communication in healthcare and it facilitates the fast delivery of messages and information." However, the article still notes that “email's ubiquity has brought challenges. It has changed the way we get things done, and working days can be dictated by the receipt and reply of multiple email messages, which drown out other priorities.” In such an environment, impersonation attacks thrive, leveraging familiarity, authority, and time pressure to bypass both technical safeguards and human judgment.

What are impersonation attacks?

Impersonation attacks are a form of social engineering in which an attacker poses as a legitimate individual or organization to deceive the email recipient into sharing information, granting access, or acting on fraudulent requests.

A common subtype is Business Email Compromise (BEC). In BEC, attackers will spoof or fake sender identities, like executives, clinicians, or vendors, to convince staff to perform actions such as:

• Sending sensitive data
• Transferring funds
• Sharing login credentials
• Approving fake invoices

Impersonation attacks often don’t carry malicious attachments or clear phishing links. Instead, they rely on trust, familiarity, and urgency, making them hard to spot with basic security measures alone. According to Paubox’s 2025 Top Healthcare Email Attacks Report, impersonation, including BEC, was consistently one of the top attack patterns within email-related breaches, alongside credential theft and vendor exposure.

Why healthcare remains a high-value target

Healthcare organizations are consistently attractive targets to attackers for several reasons:

Valuable personal health information (PHI)

Healthcare organizations hold some of the most sensitive data, including medical histories, insurance information, Social Security numbers, and more. According to NAHUM, “Personal medical data is said to be more than ten times as valuable as credit card information. PHI has such a high value because it contains highly sensitive information, such as social security numbers, birth dates, addresses, credit card numbers, telephone numbers and medical conditions. This data is incredibly valuable on the black market because, unlike a stolen credit card that can be easily canceled, most people are unaware that their medical information has been stolen.”

The consequences of PHI exposure are severe and long-lasting. Stolen PHI can enable medical identity theft, insurance fraud, and extortion schemes that are notoriously difficult to reverse. NAHUM notes that once medical identity theft is discovered, “it can take years to undo the damage caused,” and victims often face prolonged administrative and financial hardship. Alarmingly, only 10% of victims report achieving a satisfactory resolution, and those who do spend more than 200 hours navigating the process. This is why PHI is so highly prized by attackers, and why healthcare organizations face disproportionate risk from impersonation-driven email attacks that can lead to its exposure.

Email culture with high urgency

In a clinical setting, time is often of the essence. Emails that appear to come from colleagues or leadership with urgent requests can easily prompt quick compliance without thorough verification, especially when patient outcomes are perceived to be on the line.

Complex third-party ecosystems

Healthcare organizations work with insurers, billing vendors, labs, and technology providers, who may widen the attack surface and increase the chances of impersonation. As Paubox reports, vendors and business associates were responsible for 28% of all email-related incidents reported to the HHS. This means nearly one in three breaches involved a third-party. Attackers exploit this connectedness to create believable deception.

Underreported threats and human factors

Despite ongoing security training, many healthcare email threats go undetected or unreported. A recent Paubox report found that only about 5% of phishing and impersonation attempts are reported to security teams, meaning 95% go uninvestigated until actual damage occurs.

Read also: Healthcare email breaches in 2025: trends and prevention strategies

Consequences of impersonation attacks

The impacts of impersonation attacks in healthcare email can be severe and multifaceted:

Regulatory penalties and reporting obligations

Email breaches involving PHI typically qualify as reportable data breaches under regulations like HIPAA. As the U.S. Department of Health and Human Services (HHS) notes, “A covered entity must notify the Secretary if it discovers a breach of unsecured protected health information.” The consequences of PHI exposure include regulatory investigations, civil monetary penalties, and corrective action plans. The consequences are even more severe if email security controls are found to be inadequate. Additionally, covered entities may be required to notify affected individuals and, in large-scale breaches, issue public notices. Paubox has reported that in healthcare email breach cases between January 1, 2024, and January 31, 2025, total fines and settlements have exceeded $9 million due to failures in email security.

Financial costs

Data breaches continue to be among the most expensive across industries. According to the 2025 IBM Cost of a Data Breach Report, the average cost of a data breach is $4.4 million. In the healthcare industry, the cost, as reported by IBM, “Reached an all-time high of 4.45 million USD in 2023, which is a 15% increase over the past three years.” With average costs per incident reaching millions of dollars, healthcare organizations can face long-term financial and operational strain.

Patient trust and care integrity

Loss of patient trust after a breach can impact ongoing patient engagement, care satisfaction, and overall reputation. As stated in the study A systematic analysis of failures in protecting personal health data: A scoping review, “Data breaches illustrate the security vulnerabilities of health systems, which in turn lead to patients developing a negative perception of the health system’s ability to safeguard their privacy.” Thus, it is the responsibility of healthcare organizations to ensure privacy and minimize breach risk.

See also: HIPAA Compliant Email: The Definitive Guide (2026 Update)

Defending against impersonation attacks

Since impersonation attacks often exploit human and procedural weaknesses, the solution requires a layered approach that combines technology, policy, and awareness:

• Strengthen email identity validation: Implement email authentication protocols like SPF, DKIM, and DMARC to drastically reduce spoofing risk and identify spoofed or malicious senders before they hit inboxes.
• Adopt advanced email security solutions: Platforms that use machine learning and identity analysis, like Paubox’s inbound email security, can detect unusual sender patterns and prevent impersonation attempts from reaching users.
• Require multi-Factor authentication (MFA): MFA makes credential compromise less effective, even when attackers gain access to passwords. Organizations must ensure MFA is enforced for all critical systems, including email.
• User training: Ongoing training and simulated phishing tests help staff recognize suspicious emails and understand reporting procedures. As research shows many attacks go unreported, organizations should encourage a culture of reporting all suspicious activity.

Read also: The move from traditional defences to defensive AI

FAQS

What types of impersonation attacks are most common in healthcare?

Common types include:

• Executive impersonation, also known as BEC
• Clinician or staff impersonation requesting patient data
• Vendor or business associate impersonation involving invoices or payment changes
• IT or helpdesk impersonation asking users to “verify” credentials

How do attackers make impersonation emails look legitimate?

Attackers often research healthcare organizations extensively, using publicly available information such as staff directories, job titles, press releases, and vendor names. They may spoof display names, use lookalike domains, or reply within existing email threads to make messages appear authentic.

Do impersonation attacks lead to HIPAA violations?

If an impersonation attack results in unauthorized access, use, or disclosure of PHI, it may constitute a reportable breach under HIPAA. Covered entities may be required to notify affected individuals, HHS, and, in some cases, the media.