Vishing: How to Protect Your Business from Phone-Based Phishing

Last updated: March 2026

Most people have heard of phishing emails by now. Fewer are prepared for the phone call version. Vishing – voice phishing – uses phone calls instead of emails to trick people into handing over passwords, account numbers, or remote access to company systems.

It works because a live human voice creates pressure in ways an email cannot. The caller sounds professional. They claim to be from your bank, a software vendor, the IRS, or even your own IT department. They create urgency. And they catch people off guard because most employees have been trained to watch for suspicious emails, not suspicious phone calls.

---

How Vishing Works

A vishing attack typically follows this pattern:

1. Research – The attacker gathers information about your company from LinkedIn, your website, social media, or data from previous breaches
2. Spoofing – They spoof a phone number so caller ID shows a legitimate-looking source (your bank, a vendor, a government agency)
3. The call – They contact an employee using a rehearsed script designed to create urgency, fear, or a sense of authority
4. The ask – They request sensitive information (login credentials, account numbers, Social Security numbers) or ask the employee to install remote access software
5. Exploitation – Once they have what they need, they access accounts, transfer funds, or establish a foothold in your network

Common vishing scenarios your employees will encounter:

• “This is your bank’s fraud department” – Caller claims suspicious activity on your business account and needs to “verify” account details
• “IT support here, we detected malware on your system” – Caller asks the employee to install remote access software or provide login credentials
• “This is the IRS / state tax authority” – Caller threatens penalties or legal action unless immediate payment is made
• “I’m calling from [vendor name] about your renewal” – Caller impersonates a known vendor and asks for payment information
• “This is [executive name]’s assistant, they need you to wire funds immediately” – Caller impersonates someone in leadership to pressure an employee into a financial transaction

---

Why vishing is getting worse

Attackers can now clone a person’s voice from a short audio sample – pulled from earnings calls, conference talks, YouTube videos, even voicemail greetings. When your employee hears what sounds exactly like the CEO on the other end of the line, why would they question it?

On top of that, making thousands of spoofed calls costs almost nothing through VoIP services. Caller ID can be set to display any number the attacker wants.

Vishing also increasingly works as part of a combo. The target gets a phishing email or text first (“Call this number to resolve your account issue”), so when the phone rings, the call feels expected rather than suspicious.

Remote work has made things worse too. When everyone is working from home, there’s no walking down the hall to check whether the IT department actually called. Unusual requests get handled over the phone without a second thought.

---

Warning Signs of a Vishing Call

Train your team to watch for these red flags:

• The caller creates artificial urgency (“This must be handled right now or your account will be locked”)
• They ask for passwords, PINs, one-time codes, or Social Security numbers – legitimate organizations do not ask for these over the phone
• They resist verification (“I can’t give you a callback number, this is time-sensitive”)
• The caller ID looks right, but the caller cannot answer basic questions about your account or relationship
• They ask you to install software or grant remote access
• They pressure you to bypass normal procedures (“Don’t bother going through your manager, I already cleared it with them”)
• The call comes at an unusual time or from an unexpected department

---

Defense Checklist

Employee Training

• [ ] Include vishing scenarios in your regular security awareness training, not just email phishing
• [ ] Use realistic role-play exercises where employees practice handling suspicious calls
• [ ] Share real-world vishing examples and case studies relevant to your industry
• [ ] Train employees that caller ID can be spoofed and should never be trusted as sole verification
• [ ] Make it clear that no legitimate caller will ever ask for passwords, PINs, or one-time codes

Verification Procedures

• [ ] Establish a call-back policy: if someone requests sensitive information or action, hang up and call them back at a known, verified number (not the number they provide)
• [ ] Require a second person to approve any financial transactions or access grants initiated by phone
• [ ] Maintain an up-to-date contact directory for vendors, banks, and partners so employees can verify callers independently
• [ ] Create a code word or internal verification question for calls between departments or offices

Technical Controls

• [ ] Enable multi-factor authentication (MFA) on all critical accounts – even if a password is compromised over the phone, MFA blocks unauthorized access
• [ ] Implement call screening or filtering for your business phone system
• [ ] Consider call recording for inbound calls to sensitive departments (finance, IT helpdesk) – check your state’s recording consent laws first
• [ ] Use Cisco Umbrella or similar DNS filtering to block malicious domains that vishing callers may direct employees to visit

Reporting

• [ ] Create a simple, blame-free process for reporting suspicious calls (dedicated email address, Slack channel, or internal form)
• [ ] Log all reported vishing attempts to identify patterns and repeat targeting
• [ ] If a vishing attempt involves a suspicious email or text message as part of the attack, forward it to ForwardToSafety.com for verification
• [ ] Report vishing attempts to the FTC at reportfraud.ftc.gov

---

What to Do If an Employee Falls for a Vishing Call

1. Act immediately – The faster you respond, the more damage you can prevent
2. Change compromised credentials – Reset any passwords or PINs that were shared
3. Alert your bank or financial institution if financial information was disclosed
4. Disconnect remote access if the employee installed any software at the caller’s request
5. Scan affected systems for malware or unauthorized access
6. Document everything – Write down what was said, what information was shared, and the phone number displayed
7. Report the incident – File a report with the FTC and notify your cyber insurance carrier
8. Brief the team – Use the incident (without naming the employee) as a learning opportunity for everyone

---

Vishing vs. Smishing vs. Phishing

Attack Type	Channel	What to Watch For
Phishing	Email	Suspicious links, spoofed sender addresses, urgent requests
Vishing	Phone call	Caller ID spoofing, pressure tactics, requests for credentials
Smishing	Text message (SMS)	Shortened URLs, fake delivery notifications, “verify your account” messages

All three rely on the same social engineering tricks. The delivery method changes, but the playbook doesn’t. Your training should cover all three.

---

Key Takeaways

1. Vishing is growing because AI voice cloning and cheap VoIP make it easy and effective
2. Caller ID means nothing – it can be spoofed in seconds
3. No legitimate organization will ask for passwords, PINs, or one-time codes over the phone
4. A call-back verification policy is your strongest defense
5. MFA protects accounts even when passwords are compromised by phone
6. Create a blame-free reporting culture so employees speak up immediately

---

Need help building a security awareness program that covers vishing, phishing, and social engineering? Contact us at craigpeterson.com or call 603-966-4607 x5050.