What is Vishing in Cybersecurity: Meaning, Examples & Prevention Tips

Vishing is short for voice phishing and is a type of social engineering scam. In this scam, an attacker uses a phone call to trick the recipient into sharing sensitive information, approving a transaction, or giving them access they should never have. The caller may pretend to represent a bank, government agency, or any other trusted party and may use urgency or fear to make the call sound legitimate.

Although the basics remain the same, vishing fraud has become more convincing. Today, scammers use caller ID spoofing and AI-generated voice cloning to create fake calls that sound more credible and almost identical to a real person.

What is a Vishing Attack?

Vishing, meaning a phishing attack that happens over a voice call, involves an attacker who may pose as someone the recipient trusts. The attacker may make an urgent request or tell a convincing story to build trust. All these are designed to take an action before the caller’s identity is verified.

Phishing is a broader type of social engineering conducted through deceptive digital communication. Vishing uses voice, while smishing uses text messages. The goal is to obtain sensitive information, money or access.

AI-powered vishing attacks are reshaping the cyber threat landscape. Voice-cloning tools let attackers create audio that sounds like a real person. This removes one of the oldest clues people relied on when judging suspicious calls, which is recognizing whether the voice sounds familiar.

The scale of the risk is becoming harder to ignore. Figures from CrowdStrike’s 2025 Global Threat Report show that vishing attacks skyrocketed 442% between the first and second half of 2024.

Common Vishing Scenarios Businesses Should Know

Vishing attacks can take different forms. The following vishing example scenarios show how these tactics can target businesses.

Bank or Financial Institution Impersonation

Here, the caller claims to work for your bank or another financial institution and says suspicious activity has been recorded on your account, then pressures you to verify a transaction or follow their steps.

Case Study: In 2024, an attacker posing as a bank employee managed to fraudulently withdraw £66,100.

According to the Cyber Security Center for the Isle of Man (CSC), a company employee got a call on the organization’s mobile from someone pretending to be from NatWest Bank.

During the call, the employee noticed an unfamiliar remote-access tool on the screen. Although the company’s IT provider found no malware or unauthorized software, £66,100 had already been withdrawn.

What could have been done: Unusual account activity should have been verified directly through the bank’s official contact channels. Additionally, unfamiliar remote-access software or requests to access an account during a call should have been treated as a warning sign.

IT or Help Desk Impersonation

In an IT or help desk scam, the attacker pretends to be from your internal IT team or a tech support provider. They claim that your account has been compromised and ask you to approve an MFA request. They may then install remote-access software or reset your password.

Case Study: Threat actor Storm-1811 using a vishing scam to impersonate IT or help desk personnel

In 2024, Microsoft observed that the threat actor Storm-1811 was using vishing to impersonate IT or help desk personnel and gain access to Microsoft Quick Assist.

During the call, the attackers persuaded employees to enter a security code into Quick Assist and approve screen sharing or remote control. Once access was granted, the attackers used additional tools and malware, with some attacks ultimately leading to Black Basta ransomware.

What could have been done: Establishing a strong helpdesk defense system, such as mandatory out-of-band verification and using tools to detect live-call voice anomalies, can help. Employees should also avoid approving unexpected remote-support requests, especially through an unsolicited call.

Executive or Employee Impersonation

This type of vishing in cybersecurity plays on two things people find hard to ignore: authority and urgency. The scammer poses as a CEO, CFO or senior manager and demands a quick wire transfer, sensitive company data, or a policy exception.

Case Study: MGM Resorts cyberattack 2023

In 2023, a threat group reportedly used a vishing technique to impersonate an MGM Resorts employee. Attackers researched an MGM employee on LinkedIn, then called the IT help desk, pretending to be that person. Once the help desk handed over login credentials, they gained access to MGM’s systems. The attack disrupted hotel and casino operations and ended up costing the company about $100 million, according to MGM’s own SEC 8-K filing.

What could have been done: Employee identities should have been verified through independent checks before account access was granted or reset. Help desk staff should also have followed stricter procedures.

Types of Vishing Fraud

Vishing takes several forms, depending on what the attacker knows and the technology they use:

• Wardialing: An older technique that uses automated dialing to find active phone lines or potential targets.
• VoIP (Voice over Internet Protocol): Attackers use internet-based calling services that are inexpensive, make mass calling easy, and let attackers operate from almost anywhere.
• Caller ID Spoofing: Caller ID spoofing is one form of vishing where scammers fake what appears on the recipient’s screen, such as the company’s internal extension or the bank’s official support line.

Red Flags of a Vishing Attack

Spotting these warning signs early can stop a vishing attack before it starts:

• Extreme Urgency: The caller insists on acting immediately to avoid a system lockout, legal trouble or financial loss.
• Requests for MFA Codes: The caller asks for the One-Time Password (OTP) or approves a push notification on your device.
• Unsolicited Technical Help: An unexpected call claims that your computer is infected or the IT team needs remote access to fix the problem.
• Pressure to Bypass Policy: The caller asks to skip dual-authorization steps or the usual validation process.
• Audio Inconsistencies: Odd pauses, robotic audio glitches or faint synthetic tones that hint at an AI voice clone.

How to Prevent Vishing Attacks?

Verify High-Risk Requests Through a Separate Channel

Never act on something sensitive, such as a wire transfer, a confidential request or a credential change, based only on an incoming call. Check the request through a trusted channel you already use.

For example, if an executive receives a call from a vendor demanding an urgent transfer of funds, the request must be confirmed directly using an established and separate channel before making the payment.

Never Share MFA Codes

A legitimate bank, employer, or service provider will not ask you to read one over the phone. If someone requests a code, avoid sharing it, and verify the activity through an official channel.

For example, an attacker may impersonate someone from the IT support team and may claim that a login problem requires the employee to share the MFA code. For such situations, employees must be trained to treat a verbal MFA code request as an account takeover attempt. Additionally, security training should include fake voice phishing calls, not just the usual email examples. Employees need to understand how these scams work and what to watch for.

Don’t Treat Caller ID as Authentication

Caller ID can be helpful, but seeing a familiar number does not mean the person on the other end is genuine.

Telecom standards like the STIR/SHAKEN protocol give carriers a way to check whether a caller has the right to use a number, but it is not a complete defense against vishing scams. Scammers can rely on targeted calls or compromised VoIP accounts. Always treat incoming calls that request sensitive data as high-risk, regardless of the number displayed or who appears on your device screen.

Use Detection Tools

Relying on traditional methods or tools to detect vishing fraud may be insufficient, as attackers may now use more advanced approaches, including AI voice cloning. Hence, tools like Diopter monitor incoming audio for synthetic voice and line anomalies in real time. That means deepfakes and spoofed calls can be caught before scammers cause any harm or losses.

How Diopter Helps Detect Vishing and Voice Impersonation

Standard security tools protect email, endpoints, and network activity, but vishing attacks can slip through these gaps.

Diopter covers that blind spot by analyzing voice interactions in real time, helping your team spot impersonation, manipulation and fraud.

For voice deepfake detection, Diopter’s scoring pipeline breaks speech into short, consecutive segments and checks for signs commonly left behind by voice-cloning and text-to-speech systems. The call is scored from start to finish, so security teams can receive a risk alert while the conversation is still happening.

Beyond voice analysis, Diopter can also flag requests that do not fit regular policy controls, such as wires above approved limits, unexpected MFA resets, or skipping the usual approval process.

By analyzing the conversation as it unfolds, Diopter surfaces these warning signs early. That gives teams a chance to pause a suspicious request before it becomes credential theft, unauthorized payments or other losses.

Why Does a Vishing Attack Matter for Your Business?

Understanding vishing fraud is a good starting point. The bigger worry is what happens when an attacker gets through.

A single convincing call can let criminals get around security controls, break into company systems, steal sensitive data, or drain financial resources within minutes. And with AI making vishing easier to pull off and harder to spot, traditional detection processes are no longer enough.

Equipping your organization with strict verification policies, employee training, stronger authentication practices, and real-time voice inspection tools like Diopter is essential to secure your business against modern voice fraud.

FAQs

More questions answered in our voice fraud and vishing FAQ.