Data Security

How to Protect Yourself From SIM Swapping Attacks

February 15, 2024

What is a SIM Swapping Attack?

A SIM swapping attack, also known as SIM hijacking, is a type of identity theft where a cybercriminal exploits weaknesses in mobile carrier customer service systems to take over the target’s phone number.

The attacker convinces the mobile carrier to transfer or “port” the victim’s phone number to a SIM card controlled by the attacker. This gives the attacker access to any online accounts secured by texts or phone calls, such as online banking or email.

SIM swapping enables attackers to bypass traditional security measures like two-factor authentication. With control of the victim’s phone number, the attacker can reset account passwords, generate approval codes for transactions, or intercept verification texts and calls required to access online accounts.

How SIM Swapping Works

SIM swapping scams typically unfold in three steps:

1. Gathering Personal Information

The first phase involves gathering background information on the potential victim through social engineering techniques like phishing or checking public records.

Cybercriminals look for phone numbers, addresses, social security numbers, and other personal data to build a profile of the target. This information helps convince the mobile carrier the attacker is who they claim.

2. Contacting Mobile Carrier Customer Support

Next, the attacker impersonates the victim and contacts the target’s mobile carrier pretending to be them. They provide personal information collected in the previous step to “verify” their identity.

The attacker reports their phone was lost or stolen and requests that the number be ported to a SIM card controlled by the hacker. Since they appear legitimate, the mobile carrier complies with this request.

3. Taking Over Accounts

With control of the victim’s phone number, the attacker can now reset passwords, generate approval codes, and intercept verification messages for the target’s online accounts.

They use this access to steal money, cryptocurrency, or sensitive personal information. In some cases, the victim may not even realize their accounts were compromised for days or weeks.

Why SIM Swapping Is a Rising Threat

SIM swapping has emerged as a growing cyber threat for several reasons:

Reliance on phones for authentication – As more accounts require phone-based two-factor authentication, phone numbers have become lucrative targets.
Vulnerabilities in customer support – Social engineering tactics often succeed in fooling mobile carrier support staff untrained to detect sophisticated fraud.
High payout – Once successful, attackers gain access to bank accounts, cryptocurrency wallets, and other accounts containing valuable assets.
Difficulty tracing cryptocurrency – Cryptocurrency accounts compromised via SIM swapping are attractive targets since transactions are difficult to reverse.
Information leaks – Personal data breaches provide information that enables more convincing social engineering attempts.

Most Common SIM Swapping Victims

While anyone with valuable online accounts secured by their phone number is at risk, some common targets include:

Cryptocurrency holders – Crypto wallet accounts relying on phone verification are frequently targeted.
Business executives – Access to corporate accounts makes business users attractive marks.
Technology industry insiders – Those perceived as holding valuable intellectual property or insider information.
Celebrities – Public figures with social media accounts holding compromising or sensitive info.
Youth – Younger demographics tend to have weaker identity security practices.

Warning Signs of a SIM Swap Attack

Being alert for any of these signs of suspicious activity can help detect if you are the victim of a SIM swap in progress:

Sudden loss of cellular connectivity showing “No Service”.
Inability to make or receive phone calls and text messages.
Password reset emails or texts for accounts you didn’t request.
Unfamiliar devices logged into your online accounts.
Bank account withdrawals you didn’t authorize.
Friends receiving texts or calls from your number when your phone was elsewhere.

How to Protect Yourself from SIM Swapping

Fortunately, there are steps you can take to reduce your risk:

Use Non-Phone Two-Factor Authentication Options When Available

Where possible, opt for authentication apps, security keys, or backup email addresses rather than phone-based two-factor authentication.
This limits what attackers can access by porting your SIM.

Avoid SMS for Sensitive Communications

When given the choice, don’t use text messages for one-time passwords, bank codes, or other sensitive info. Apps are more secure.
Text messages can be intercepted if your SIM is ported.

Set Up Account Activity Alerts

Configure your online accounts to alert you via push notification or email for important account activity like password changes.
This helps quickly detect unauthorized access.

Limit Personal Info Shared Publicly

Be cautious about sharing details like phone numbers, addresses or birthdates on social media.
This information aids social engineering attempts.

Add Account Security Measures

Take advantage of advanced account security options like backup verification methods, fraud prevention, and account lockouts to deter attackers.
Make attacker’s job harder by limiting account access attempts.

What to Do If You Are SIM Swapped

If you suspect unauthorized SIM swapping activity:

Immediately contact your mobile carrier – Report the fraudulent SIM swap and request they immediately reinstate your original SIM.
Reset account passwords – Once you regain phone service, reset the passwords for all compromised accounts using a device you know is secure.
Scrutinize account activity – Review accounts for any unauthorized transactions, password changes, or other suspicious access.
Notify contacts – Let friends and family know to expect potential unfamiliar messages from your number.
Contact relevant institutions – If bank accounts were accessed, notify your bank. For identity theft, report to the FTC.
Consider legal options – Consulting a lawyer may be appropriate depending on your specific case and details.

Key Takeaways on Preventing SIM Swapping Attacks

SIM swapping lets attackers bypass two-factor authentication by porting your phone number.
Attackers socially engineer mobile carriers to transfer your number to them.
Once successful, they can access bank accounts, emails, and other online accounts.
You are at higher risk if you have valuable online accounts protected by your phone number.
Opt for app-based two-factor authentication rather than SMS when possible.
Monitor online accounts closely for unauthorized access attempts.
Immediately contact mobile carrier and account providers if SIM swapped.

Conclusion

As online accounts increasingly rely on phone numbers for account security, users must understand emerging threats like SIM swapping. While challenging to prevent outright, following best practices around two-factor authentication methods, account monitoring, and limiting personal details shared online can help users minimize their overall risk. Being alert to the warning signs of SIM swap fraud and acting quickly if it occurs can also significantly limit resulting damage.