The MFA Level-Up: Why SMS Codes Are No Longer Enough (and What to Use Instead)

For years, enabling Multi-Factor Authentication (MFA) has been one of the most effective ways to protect user accounts and devices. While MFA is still a critical security control, the threat landscape has evolved, and not all MFA methods offer the same level of protection anymore.

The most widely used form of MFA, four- or six-digit codes delivered via SMS, is familiar and convenient. It is certainly better than passwords alone. However, SMS is an aging technology that was never designed for secure authentication, and attackers have learned how to reliably exploit its weaknesses. For organizations that handle sensitive or regulated data, SMS-based MFA is no longer enough. To stay ahead of modern threats, businesses must adopt phishing-resistant MFA solutions.

SMS authentication relies on cellular networks and legacy telecommunications protocols such as Signaling System No. 7 (SS7), which were built decades ago without today’s security threats in mind. These weaknesses make SMS an attractive target for attackers.

Cybercriminals are well aware that many businesses still rely on SMS MFA. By exploiting SS7 vulnerabilities, attackers can intercept text messages without ever touching the victim’s phone. Techniques such as message interception, redirection, and injection can occur entirely within carrier infrastructure.

SMS codes are also easily defeated by phishing. If a user is tricked into entering their username, password, and SMS code on a fake login page, attackers can capture all three in real time and immediately access the legitimate account.

For Small/Medium Businesses in Orange County, CA, these risks are no longer theoretical. Here at Newport Solutions, we believe that modern identity security must go beyond convenience and focus on resilience against real-world attack methods.

Interested in our services, check out details here https://newport-solutions.com/it-support 

Understanding SIM Swapping Attacks

One of the most serious threats to SMS-based MFA is SIM swapping. In a SIM swap attack, a criminal impersonates a victim and contacts their mobile carrier, claiming their phone has been lost or damaged. The attacker then convinces support staff to transfer the victim’s phone number to a new SIM card they control.

Once successful, the victim’s phone loses service, and the attacker begins receiving all incoming calls and SMS messages, including MFA codes for email, banking, and cloud services. With access to these codes, attackers can reset passwords and fully compromise accounts.

SIM swapping doesn’t require advanced technical skills. Instead, it relies on social engineering and exploiting weaknesses in carrier identity verification processes, making it a low-effort attack with devastating consequences.

Why Phishing-Resistant MFA Is the New Gold Standard

To counter these threats, organizations must remove human error and insecure channels from the authentication process. Phishing-resistant MFA achieves this by using cryptographic authentication methods that bind login attempts to specific domains and devices.

One widely adopted standard is Fast Identity Online 2 (FIDO2). FIDO2 uses public key cryptography to create passkeys that are uniquely tied to a device and a legitimate service domain. Even if a user clicks on a phishing link, the authentication process will fail because the domain does not match the original cryptographic record.

Because phishing-resistant MFA is often passwordless, it eliminates the risk of stolen credentials and one-time passwords entirely. Attackers are forced to target the physical device itself, which is significantly more difficult than tricking a user into giving up a code.

Implementing Hardware Security Keys

One of the strongest phishing-resistant MFA options available today is the use of hardware security keys. These physical devices, similar in size to a USB flash drive, connect to a computer via USB or authenticate wirelessly with mobile devices.

During login, the user inserts or taps the key, triggering a secure cryptographic exchange with the service. There are no codes to type and nothing that can be intercepted remotely. Unless an attacker physically steals the key, they cannot gain access to the account.

Hardware keys provide exceptional protection for high-risk users such as executives, administrators, and finance teams.

Mobile Authentication Apps and Push Notifications

If hardware keys are not practical for every user, mobile authenticator apps such as Microsoft Authenticator or Google Authenticator are a strong alternative to SMS-based MFA. These apps generate codes locally on the device, removing the risk of SIM swapping and SMS interception.

However, simple push notifications can introduce another risk: MFA fatigue. Attackers may bombard users with repeated login prompts, hoping the user will approve one out of frustration or confusion.

Modern authenticator apps mitigate this risk through number matching, which requires users to enter a number displayed on their login screen into the app. This confirms that the person approving the request is physically present and initiating the login themselves.

Passkeys: The Future of Authentication

As password breaches become routine, many platforms are shifting toward passkeys. Passkeys are device-based credentials protected by biometrics such as fingerprints or facial recognition. They are phishing-resistant by design and can be securely synchronized across trusted ecosystems like iCloud Keychain or Google Password Manager.

Passkeys combine strong security with ease of use. They eliminate passwords entirely, reduce helpdesk password reset requests, and provide a seamless login experience for users while significantly improving security.

Balancing Security With User Experience

Transitioning away from SMS-based MFA requires change management. Because users are accustomed to the simplicity of text messages, introducing authenticator apps or hardware keys can initially meet resistance.

Clear communication is essential. Explaining the real risks of SIM swapping and phishing, and how these attacks directly impact both the business and employees, helps drive adoption. When users understand the “why,” they are far more likely to support the change.

A phased rollout can ease the transition for general users, but phishing-resistant MFA should be mandatory for privileged accounts. Administrators, executives, and financial staff should never rely on SMS-based authentication.

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About Newport Solutions 

Newport Solutions has been helping small businesses in Orange County, CA for almost 20 years. Our dedicated team provides comprehensive IT services, ensuring your business operates smoothly and efficiently. From IT support to cybersecurity, we've got you covered. Discover how we can become your business's IT department today. 

We proudly serve the following areas: Newport Beach, Huntington Beach, Irvine, Costa Mesa, and the greater Orange County region. 

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