Vishing

What is Vishing?

Vishing (voice + phishing) is a social engineering attack that uses voice calls or voicemail messages to trick users into revealing sensitive information, such as passwords, credit card numbers, or personal details. Vishing attacks exploit the trust people place in phone calls and the difficulty of verifying caller identity.

How Vishing Works

Attack Process

• Target identification – Gather phone numbers and personal information
• Caller ID spoofing – Forge caller ID to appear legitimate
• Script preparation – Create convincing conversation scripts
• Call execution – Make calls to target numbers
• Information extraction – Convince victims to reveal sensitive data

Common Techniques

• Caller ID spoofing – Display fake phone numbers
• Authority impersonation – Pretend to be from trusted organizations
• Urgency tactics – Create time pressure to act quickly
• Social proof – Reference other "customers" or "employees"
• Technical jargon – Use confusing technical terms

Types of Vishing Attacks

Credential Theft

• Banking calls – Fake security alerts from banks
• IT support – Pretend to be technical support
• Account verification – Request sensitive information
• Password reset – Trick users into revealing credentials

Financial Fraud

• Tax scams – Fake IRS or tax authority calls
• Investment opportunities – Fraudulent investment schemes
• Charity scams – Fake donation requests
• Lottery scams – Fake prize notifications

Corporate Espionage

• Employee impersonation – Pretend to be company employees
• Vendor calls – Fake calls from business partners
• System access – Request remote access to systems
• Information gathering – Collect sensitive business information

Detection and Prevention

Technical Controls

• Caller ID verification – Verify caller identity
• Call blocking – Block known malicious numbers
• Voicemail security – Secure voicemail systems
• Call recording – Record suspicious calls for analysis

User Education

• Security awareness training – Phone security education
• Verification procedures – How to verify legitimate calls
• Red flags identification – Recognize suspicious call patterns
• Reporting mechanisms – Report suspicious calls

Organizational Measures

• Phone security policies – Clear guidelines for phone security
• Incident response plans – Prepare for vishing incidents
• Regular training – Keep awareness current
• Threat intelligence – Stay informed about new tactics

Response and Recovery

Immediate Actions

• End suspicious calls – Hang up on suspicious callers
• Report incidents – Notify security teams
• Change passwords – If credentials were compromised
• Monitor accounts – Watch for unauthorized activity

Investigation Steps

• Call analysis – Examine call details and recordings
• Caller ID analysis – Investigate spoofed numbers
• Impact assessment – Determine scope of compromise
• Documentation – Preserve evidence for analysis

Best Practices

• Verify caller identity – Call back using official numbers
• Don't share sensitive information – Never give passwords over the phone
• Use official contact methods – Contact organizations directly
• Enable call screening – Use call screening features
• Report suspicious calls – Help protect others
• Trust your instincts – If something seems wrong, it probably is