Phone numbers have evolved into essential identifiers, akin to personal IDs and crucial for logging into numerous online services ranging from social networks to banking apps.

As such, control over these digits is pivotal, with their loss potentially leading to significant security issues for the owner. These numbers are so integrated into users’ digital identities that losing the ability to manage them could open the door to unauthorised access to important personal and financial information.

Kaspersky experts recommend the following strategies to keep users’ phone numbers secure.

According to the “Digital 2024 Global Overview Report” conducted by Kepios, there are now 5,65-billion unique mobile phone subscribers worldwide. This significant figure suggests that the majority of the world’s population has at least one phone number, and this trend continues to grow each year.

Given these facts, Kaspersky experts are highlighting the risks and responsibilities associated with managing phone lines, emphasising the need for awareness and the protective measures that can be used in scenarios where numbers can be compromised.

Safety after lost phone and SIM

When a phone is lost or stolen with the SIM card still inside, it presents a distressing scenario. Not only is there the immediate loss of a personal device, but the situation also poses a risk to the owner’s digital security. Since SIM cards can easily be transferred to another phone, the absence of PIN protection leaves personal accounts linked to that phone number vulnerable to unauthorised access.

In events like these, the initial step should be to contact the service provider to block the SIM card. Once the SIM card in the lost device is deactivated, it no longer poses a risk of misuse to its owner. The next step following the blocking will be obtaining a new SIM with the same phone number.

For e-SIM users, the process involves contacting the provider to deactivate the SIM on the lost device and arranging for a connection setup on a new one.

These proactive measures help minimise the impact of the loss and safeguard personal information effectively.

Securely managing phone number changes

When the need arises to switch to a new number − perhaps due to persistent spam or scam calls or unwanted attention from others − it’s crucial to manage the transition thoughtfully. The current number likely serves as a username or key recovery option for various important services, including social networks and banking apps.

Mobile carriers often recycle numbers and assign the old ones to someone else after a period. If the accounts linked to that number haven’t been reassigned, the new owner could potentially access them, putting personal information at risk.

It’s advisable not to rush the process. Starting by securing a new line while keeping the old one active will be the safest option. This overlap period is essential for smoothly decoupling accounts from the previous number.

Utilising a password manager can be extremely helpful during this phase: it can help identify which services use the number as a login credential. Additionally, reviewing the history of incoming SMS for confirmation codes can provide clues about which services need updating.

Porting out scams

Port-out scams start when a scammer gathers enough personal information to impersonate someone. They often get this data through phishing − sending fake emails that resemble those from a real mobile provider asking for personal details on a fraudulent website − or vishing, where they call pretending to be from a mobile phone company and deceive the person into divulging sensitive information.

Once they have names, addresses, and Social Security/ID numbers, scammers can make the mobile carrier switch the phone number to a new SIM card they control. This allows them to intercept all messages sent to that number, like one-time passcodes, enabling the scammers to access financial and personal accounts. Victims usually don’t realise they’ve been scammed until they lose cellphone service or notice strange activities on their accounts.

To guard against these scams, it is advisable to be cautious with emails and calls requesting personal details or urging quick action.

Verify any dubious communication by directly contacting the provider through official channels. If a SIM swap is suspected, contact the carrier immediately to secure the account and monitor financial statements for unauthorised transactions.

Adding a unique PIN or password for account changes with the mobile provider also enhances protection, while employing comprehensive cybersecurity solutions, such as Kaspersky Premium, helps protect against engaging with sites aimed at obtaining sensitive users’ data.

“In today’s interconnected world, phone numbers have transformed into one of the most crucial personal identifiers, akin to a digital fingerprint,” comments Anna Larkina, web content analysis expert at Kaspersky.

“It’s essential to approach its security with the utmost care. By recognising the risks of misuse and the potential for compromise, we can protect ourselves from significant future distress and loss. Moreover, vigilance coupled with modern cybersecurity solutions form a robust defense against various threats.”