Smishing and Vishing: How to Defend Against Text and Voice Phishing

Hero Summary

Smishing is phishing delivered by SMS or messaging apps; vishing is phishing delivered by phone call. Both bypass email security filters and exploit trust in phones and personal devices. Attackers impersonate banks, delivery firms, government agencies, vendors, help desks, and colleagues, creating urgency to make the target share a code, click a link, install software, or move money. Defence combines simple verification rules — never act on an inbound request without checking through a number you already trust — with training, simulation across text and voice, and controls such as phishing-resistant multi-factor authentication.

Executive Summary

Email is the best-defended phishing channel, so attackers increasingly use channels with fewer controls. FBI IC3's 2025 report lists tech and customer support fraud at 47,794 complaints and $2,134,675,818 in reported losses and government impersonation at 32,424 complaints and $797,943,193 — fraud types that commonly rely on calls and texts, although IC3 does not label them as smishing or vishing. The same report adds an "AI Related" descriptor, with 22,364 complaints and $893,346,472 in losses, reflecting how AI is changing how convincing these scams are. This guide explains how smishing and vishing work, how to recognize them, how AI voice cloning changes the picture, and what organizations and individuals can do.

What are smishing and vishing? {#what}

• Smishing (SMS + phishing) uses text messages or messaging apps to deliver a deceptive link, phone number, or request.
• Vishing (voice + phishing) uses phone calls, and sometimes voicemail, to talk a target into revealing information or taking an action.

Both are forms of social engineering: the attacker manipulates the person rather than exploiting software.

Why attackers use text and voice {#why}

• They bypass email filters and gateways.
• Phones feel personal and urgent. A text or call demands immediate attention.
• Links are harder to inspect on a phone, and shortened URLs hide destinations.
• Caller ID and sender names can be spoofed, making a message appear to come from a trusted number or brand.
• Personal devices often sit outside corporate controls, especially in bring-your-own-device environments.
• Real-time conversation allows pressure and persuasion that email does not.

How smishing works {#smishing}

Typical smishing lures include:

• Delivery and parcel notices asking for a fee or address confirmation.
• Bank and payment alerts about suspicious transactions or blocked cards, with a link to a fake page.
• Government and tax notices about refunds, fines, or account problems.
• Workplace-themed messages impersonating HR, IT, or a manager, such as a request to "urgently buy gift cards" or approve a login.
• Multi-factor authentication abuse: the attacker triggers a login prompt and texts the victim to "confirm" it or to read out the code.

The link usually leads to a convincing fake login page that harvests credentials and one-time codes, or to a download that installs malware.

How vishing works {#vishing}

A vishing call typically follows a script: the caller establishes authority or familiarity (bank fraud team, IT help desk, a senior executive, a government agency), creates urgency (an account is compromised, a payment is overdue, a legal notice is pending), and then asks for something specific — a one-time code, remote access to a computer, a password, a transfer, or a change to payment details. Help-desk vishing, where the caller impersonates an employee to get a password reset or MFA change, targets the organization's support processes directly.

AI voice cloning and deepfakes {#ai}

Voice cloning tools can imitate a person's voice from a short audio sample taken from public videos, calls, or social media, and deepfake video can imitate faces. This means a familiar voice on a call is no longer proof of identity, and a convincing "urgent request from the CEO" can be fabricated. The IC3's 2025 report records 22,364 complaints and $893,346,472 in losses carrying its "AI Related" descriptor. The defence is procedural, not perceptual: do not rely on recognizing a voice or face; verify high-risk requests through an independent channel.

Warning signs {#signs}

• Unexpected contact claiming to be a bank, agency, vendor, or executive.
• Urgency or threats — act now or lose access, face penalties, or let someone down.
• Requests for one-time codes, PINs, passwords, or remote access. Legitimate organizations do not ask for these by call or text.
• Requests to move money or change payment details, especially with secrecy.
• Links that do not match the claimed organization, or shortened links.
• Pressure to stay on the line and not hang up to verify.
• Callers who know some details about you — this does not prove legitimacy, because details can be collected from public sources or earlier breaches.

Rules that work {#rules}

1. Hang up and call back on a number you already hold, such as from an official website or a card — not a number the caller gives.
2. Never share one-time codes or passwords, with anyone, for any reason.
3. Do not click links in unexpected texts; open the organization's app or type its address yourself.
4. Verify requests for money or changed payment details through a second, trusted channel.
5. Use a pre-agreed code word or procedure for sensitive requests between executives and finance teams.
6. Report suspicious calls and texts to the security team, and in India to the National Cyber Crime Reporting Portal (cybercrime.gov.in) or the 1930 helpline if money has been lost.

What organizations should do {#org}

• Set verification procedures for payments, bank-detail changes, credential resets, and MFA changes, including for help-desk staff, so a convincing voice alone is never enough.
• Use phishing-resistant MFA where possible, and do not rely on SMS codes alone. See Email Account Security Beyond Passwords.
• Harden the help desk with identity checks for resets and call-back procedures.
• Provide a simple way to report suspicious texts and calls.
• Brief executives and their assistants, who are frequent impersonation targets.
• Manage mobile devices used for work, and publish guidance on personal-device use.
• Prepare an incident plan for credential or fund-transfer fraud. See Business Email Compromise.

Training and simulation {#training}

Reading about vishing is different from handling a persuasive caller. Simulation across email, SMS, and voice builds the habit of pausing and verifying, and shows which groups — help desk, finance, executive assistants — are most exposed. See Phishing Simulation Best Practices and Role-Based Security Awareness Training.

How Threat ResQ's TRAP fits {#trap}

TRAP is the phishing simulation capability within TRISA, Threat ResQ's AI security awareness and human risk intelligence platform. It combines interactive training with continuous phishing, smishing, and vishing simulation, and feeds results into TRISA's continuous readiness scoring and its department-level and board-level reporting. Threat ResQ's Security Awareness Services provide a facilitated, human-led layer alongside the platform.

FAQ {#faq}

What is the difference between smishing and vishing? Smishing is phishing by text message or messaging app; vishing is phishing by phone call. Both use impersonation and urgency to make a victim share information, click a link, or send money.

Can I trust a voice I recognize on the phone? Not for high-risk requests. AI voice cloning can imitate a person's voice from a short sample, so verify requests for money, codes, or access through an independent channel.

What should I do if I get a suspicious text or call? Do not click links or share codes. Hang up or ignore the message, verify through an official number or app you already have, and report it to your security team. If money was lost in India, contact the 1930 helpline or cybercrime.gov.in.

Why do attackers use text and phone calls instead of email? Email is the most heavily filtered channel. Texts and calls bypass those filters, feel personal and urgent, and allow real-time pressure.

How can organizations train staff against smishing and vishing? With role-relevant training and simulation that includes text and voice scenarios, clear verification procedures for payments and credential resets, and an easy way to report suspicious contact.