Resources

What is Phone Number Spoofing?

Phone Number Spoofing is a defense evasion technique. Fraud actors manipulate caller ID so outgoing calls appear to originate from a trusted numbe; a bank, government agency, or the victim's own contact list.

Arsen Team
3 minutes read
What is Phone Number Spoofing?

Phone Number Spoofing maps to Defense Evasion in the MITRE F3 Framework. It is one of the primary technical enablers of vishing attacks, making a fraudulent call appear to come from a number the recipient already trusts.

Sub-techniques

Sub-technique Target Goal
Official Phone Number Spoofing Individuals / customers Impersonate a bank, government agency, or law enforcement
Customer Phone Number Spoofing Financial institution staff Impersonate a legitimate account holder to bypass verification

How does official phone number spoofing work in practice?

A fraud actor calls a victim from a number that displays as their bank's published customer service line. The victim, seeing a familiar number, answers and trusts the caller. The attacker then uses pretexting (claiming suspicious activity, a pending transaction, or a security alert) to extract OTPs, card details, or account credentials.

How does customer phone number spoofing work?

Here the direction reverses: the fraud actor calls the bank, spoofing the phone number of a legitimate account holder. Contact centre agents who use caller ID as a verification factor may grant access, change account details, or perform transactions based on a number they believe belongs to a real customer.

Why is phone number spoofing a specific training priority?

Employees in contact centres and bank branches are the targets of customer-number spoofing. Training them to treat caller ID as an untrusted signal (and to enforce out-of-band identity verification) is a direct countermeasure. Arsen's vishing simulation platform replicates spoofed-number scenarios to build this reflex.

Key takeaways

  • Phone Number Spoofing is a Defense Evasion technique in MITRE F3 with two sub-techniques.
  • Official spoofing targets customers; customer spoofing targets bank staff.
  • It is the primary technical enabler of vishing attacks.
  • Caller ID cannot be trusted as an authentication or verification mechanism.
  • Contact centre staff need specific training to verify identity through out-of-band channels regardless of displayed number.

What is MITRE Fight Fraud Framework™ (F3)?

The MITRE Fight Fraud Framework (F3) is a curated knowledge base of tactics, techniques, and sub-techniques used by fraud actors in cyber-based financial fraud incidents. Developed by MITRE's Center for Threat-Informed Defense in collaboration with FS-ISAC, JPMorganChase, and Lloyds Banking Group, it provides a common language for fraud-fusion teams to describe, detect, and prevent financial fraud. F3 is modeled after MITRE ATT&CK® and focuses on banking institutions as its initial scope.


Book a demo

Discover why Arsen is the go-to platform for helping CISOs, security teams, and IT leaders protect their organizations against social engineering.

Frequently Asked Questions

An attacker spoofs a bank's published number to call a customer, then uses social engineering to extract OTPs, passwords, or account data. The spoofed number bypasses call-screening and creates immediate trust.

STIR/SHAKEN call authentication frameworks can flag spoofed numbers at the carrier level, but adoption is incomplete. The most reliable defence is training staff and customers not to treat caller ID as proof of identity.

Arsen's vishing simulation platform allows security teams to run realistic spoofed-number call simulations against employees and contact centre agents, measuring response rates and training users at the moment of vulnerability.

It is a Defense Evasion technique where fraud actors manipulate caller ID data so that outgoing calls display a different (typically trusted) number. It has two sub-techniques targeting customers (official spoofing) and bank staff (customer spoofing).

Continue reading

AI Vishing: Why Finance Teams Are the New Front Line

AI Vishing: Why Finance Teams Are the New Front Line

Alex Beaurepaire
Alex Beaurepaire

AI voice cloning has collapsed the cost of vishing from hundreds of dollars per targeted call to effectively zero at scale. Finance, treasury, and executive assistant teams now face the same volume of voice-based...

Vishing Training for Financial Services Teams

Vishing Training for Financial Services Teams

Thomas Le Coz
Thomas Le Coz

Protect your financial institution from voice phishing. Learn why vishing targets banking and fintech teams, the limitations of traditional defenses, and how to implement scalable, compliant simulation training to...