Multi-Factor Authentication and User Behavioral Analysis: from Identity to Behavioral Detection

The cyberattacks that companies face today have little to do with the “classic” intrusions that were widespread until a few years ago.
We are no longer dealing only with cases of technical exploits targeting known vulnerabilities, but with sophisticated attack campaigns that surgically combine multiple tactics: targeted exploiting, social engineering, advanced phishing, and increasingly convincing deepfakes capable of impersonating key corporate figures. In this complex scenario, passwords—even complex ones protected by strict policies—are no longer enough to ensure security.

To maintain business continuity and ensure compliance with regulations such as NIS2, DORA, or ISO 27001, organizations must adopt a dynamic, multi-layered protection model. This model must not only prevent unauthorized access but also detect weak signals and anomalous behaviors that may emerge after authentication. In this context, two controls stand out as particularly effective: Multi-Factor Authentication (MFA) and User Behavioral Analysis (UBA). The former significantly reduces risks linked to credential theft, while the latter intercepts suspicious behavior even when login is successful. Together, they create an adaptive defense strategy capable of responding both to trivial compromises and to persistent, targeted attacks.

Multi-Factor Authentication: necessary but no longer sufficient

In recent years, Multi-Factor Authentication has become a fundamental requirement in any security architecture. Its principle is clear: to access a critical system, knowing a credential is not enough; it is also necessary to validate a second or even third factor, linked to the possession of a device, a phone number, or the biometric identity of the user (fingerprint, face ID, etc.).

Available technologies cover several levels, ranging from OTPs generated by dedicated applications, to push notifications that simplify the user experience, up to the most modern FIDO2/WebAuthn standards, which enable passwordless scenarios and leverage hardware keys and biometrics. There are still implementations based on SMS or email OTPs, which remain widespread but expose organizations to well-known risks such as SIM swapping or targeted phishing.

This form of authentication is an important barrier against scenarios such as Business Email Compromise (BEC): an attacker in possession of credentials cannot complete access without the second factor. The same applies to fraud attempts using voice deepfakes: biometric settings or cryptographic keys cannot be replicated by manipulated audio. However, despite its effectiveness, MFA is not invulnerable. Advanced phishing with reverse proxies, MFA fatigue attacks, or session hijacking reveal its limits and show that MFA alone is no longer sufficient.

User Behavioral Analysis: intercepting weak signals

UBA addresses this gap by applying machine learning algorithms and statistical analysis to user telemetry data to build a behavioral baseline and detect significant deviations.

Imagine some concrete scenarios: a login from a country never used before, a massive file download in just a few minutes, a password change followed by an urgent wire transfer, or the use of a newb device at unusual hours. Individually, these events might seem legitimate. But when observed together, they represent warning signs of a potential compromise.

The strength of UBA lies precisely in this: turning seemingly neutral activities into contextual alerts, capable of highlighting anomalies that would escape static controls. Naturally, this approach requires constant calibration to reduce false positives and achieves maximum effectiveness when integrated with SIEM and SOAR platforms, which allow event correlation and, in many cases, trigger automated response actions.

From UBA to UEBA: extending visibility

The natural evolution of UBA is UEBA (User and Entity Behavioral Analytics), which broadens the scope of analysis beyond human users to include machines, APIs, service accounts, and communication flows. This extension is crucial to intercept lateral movements, stealth activities, and insider threats, well-documented in the MITRE ATT&CK framework.

Integrated with threat intelligence feeds and SIEM platforms, UEBA enables correlation between local anomalies and global compromise indicators, significantly improving detection capabilities against advanced actors and persistent attacks.

MFA + UBA: adaptive defense and Zero Trust

In enterprise architectures, MFA and UBA are positioned within the Identity & Access Management (IAM) perimeter, interconnected with centralized directories (Active Directory, Azure AD) and SIEM systems. MFA operates in the prevention phase, blocking unauthorized access. UBA acts in the detection & response phase, monitoring post-login activity and validating every action according to Zero Trust principles: “never trust, always verify.”

The real value emerges from integration. MFA reduces the attack surface, while UBA ensures that even a seemingly legitimate user cannot act undisturbed if deviating from their usual behavior. Consider an employee who unknowingly approves a fraudulent MFA request: the attacker enters with valid credentials. Without UBA, the intrusion would remain invisible. With UBA, however, a nighttime login from a foreign IP combined with an anomalous wire transfer triggers an immediate alert, allowing the operation to be blocked and the incident response process promptly initiated.

Conclusions

The security of digital identities can no longer rely solely on static controls. It must be adaptive, contextual, and data-driven. MFA raises the entry threshold, but UBA ensures that attackers are detected even when they operate under the guise of legitimate users.

For critical sectors such as finance, energy, insurance, or industry, adopting this combination is not just a best practice but a prerequisite for building operational resilience and meeting new regulatory obligations. MFA and UBA integration is no longer optional but the foundation of a Zero Trust strategy capable of countering today’s and tomorrow’s threats.