In the realm of telecommunication, Caller Line Identification (CLI) has long been a critical feature, allowing recipients to see the number of the incoming caller. This capability is fundamental to various services, from personal call management to business operations, and is integral to the security and trustworthiness of telecommunication networks. However, as technology evolves, so do the methods of exploiting it. CLI spoofing, where the displayed caller ID is manipulated to appear as a different number, has increasingly become a prevalent and concerning issue for operators.

CLI spoofing involves falsifying the caller ID information transmitted to the recipient’s phone. This manipulation can be done for various reasons, often malicious, such as:

• Fraud: Scammers use spoofed numbers to deceive victims into providing personal information, money, or access to sensitive databy pretending to be calling from an organization or person trusted by the target.
• Privacy Invasion: Spoofers can bypass call-blocking mechanisms, reaching individuals who might otherwise ignore unknown numbers.
• Impersonation: Attackers pose as legitimate organisations (banks, government agencies) to gain trust and exploit unsuspecting individuals.
• Harassment: Malicious entities can hide their identity while conducting harassment, unwanted sales and marketing callsor other unlawful activities.

The growing sophistication of spoofing techniques, coupled with the widespread availability of spoofing tools and services, has exacerbated the problem, making it critical for telecommunication networks to implement effective countermeasures.

The repercussions of CLI spoofing are extensive and multifaceted, affecting various stakeholders:

• Consumers: Individuals suffer from privacy breaches, financial loss, and psychological distress.
• Businesses: Companies face reputational damage, customer trust erosion, and potential financial liabilities.
• Telecom Providers: Network operators must deal with increased customer complaints, regulatory pressure, and the challenge of maintaining service integrity.
• Regulators: Authorities must continually adapt regulations and enforcement strategies to combat evolving spoofing tacticsagainst their citizens.

Given these significant impacts, developing and deploying anti-CLI spoofing solutions is not just a technological challenge but also a socio-economic imperative.

However, how is an operator to know if their anti-CLI spoofing solution is acting as intended and adequately protecting the network?

By performing CLI spoofing tests, Telecom Defence can verify if it is possible to manipulate the calling party number by initiating the calls from multiple international operators and observing if those manipulated numbers are passing through any protection measures that have been implemented on the local operator’s platforms. Cases marked vulnerable can potentially lead to CLI attacks that result in frauds based on spoofed calling number identification.

If you want to learn more about CLI spoofing tests, and would like to discuss an engagement with us, please contact us.