How does SIM Swap work? How to Prevent it?

Thousands of SIM Swap cases are registered every year. Many people lose their hard-earned money due to this fraud. This makes it extremely important for the business as well as the individual to be aware of such fraud and warning signs. Prevention and proper detection help you avoid it and its impact. Here in this blog, you will learn about how SIM Swap works and how you can prevent it.

What is SIM Swap Fraud?

In SIM swap fraud, a fraudster transfers the SIM from the victim to a new SIM they have. It helps them gain access to apps, bypass two-factor authentication, and social media accounts.

How does SIM Swap Work?

Here is how a usual SIM Swap works:

Step 1: Collecting Victim Information

In the first step, the fraudster collects the personal information about the target, such as:

Full Name

Mobile Number

Date of Birth

Aadhaar or PAN details

Banking Information

Email Address

A fraudster collects this information from various tactics, including phishing attacks, social engineering, data breaches, fake websites, or leaked databases.

Step 2: SIM Replacement Request

After collecting the information, the fraudster contacts the telecom operator for the SIM replacement. They can claim that they lost the phone, the SIM card is damaged, or a new SIM is required.

Step 3: Verification

The telecom operator will verify the customer's details. If the attacker passes the verification process. The telecom operator approves the SIM replacement request.

Step 4: Fraudulent SIM Activation and Account Takeover

The victim’s SIM card is transferred to the attacker’s SIM Card. The original SIM owner will lose network connectivity. The attacker gains control of all incoming calls and messages. Now the attacker receives the OTPs and SMS. It 

What are the types of SIM Swap Fraud?

As we have already discussed, fraudsters use multiple methods to do Sim Swap:

Social Engineering: Fraudsters contact telecom providers and impersonate the victim using stolen personal information to convince support staff to issue a replacement SIM.

Phishing-Based SIM Swap: A fraudster sends fake emails, SMS messages, or website links to steal OTPs, login information through OTPs, login credentials, and personal information. The collected information is used to request a SIM replacement.

Insider-Assisted SIM Swap: Telecom employees or agents may knowingly or unknowingly assist fraudsters in transferring a number to a new SIM Card. This type of attack can bypass standard verification procedures.

What are the Warning Signs of a SIM Attack?

These are some common warning signs that may indicate a SIM swap attack

You will not be able to send or receive messages

You will get a SIM change message 

You will get password reset, and login attempts alerts

You will not be able to access your online account

You may see unknown devices in your account activity logs

How to Protect yourself from SIM Swap fraud?

These are the prevention tips a user should follow to prevent themselves from fraud:

You should use the authenticator app instead of SMS OTP to prevent attackers from accessing the verification code.

You should set a telecom PIN to add additional security. So, the fraudster needs to fill in this PIN during the SIM swap request.

Do not share OTPs with anyone, even if they pretend they are from the bank.

Enable two-factor authentication, which will reduce easy access

Use strong passwords for all accounts to prevent credentials-based attacks

Avoid clicking suspicious links in emails, SMS messages, or social media messages.

You should use transaction and login alerts, so you will get a notification

Setting transaction limits will reduce the impact of financial loss

Immediately contact your telecom provider if you stop receiving calls or messages

What should you do if you have already been SIM-swapped?

You should immediately take these actions if you suspect:

Call your telecom provider immediately: Contact to your telecom operator to freeze or block the ported number.

Contact your bank: Call the bank's fraud helpline and request a freeze on OTP-based transactions. For UPI, contact NPCI at 1800-120-1740.

File a cybercrime complaint: Report at cybercrime.gov.in or call the national helpline 1930.

Inform Friends and Family: Fraudsters sometimes contact your relatives and friends to ask for money after gaining access.

How Businesses Can Detect and Prevent SIM Swap Fraud?

Businesses can reduce SIM swap-related fraud by implementing device intelligence, risk-based authentication, SIM binding, and account takeover prevention mechanisms. Solutions like DeepIDSDK help link user identity with trusted devices and identify suspicious login attempts before fraud occurs.

Conclusion

SIM Swap fraud is a concern for both the business and the mobile user. You should know about how the SIM Swap works and about the warning signs. It helps you in getting alert if something unfamiliar happens to you. You should also follow the prevention tips, such as using multi-factor authentication, setting telecom PIN, using the authenticator app, etc. It will add security and stop fraudsters from accessing your accounts.

FAQs

Ques: Does SIM Swapping still work?

Ans: Yes, SIM swapping is still a threat because many cases are registered regularly.

Ques: How do I prevent SIM swapping?

Ans: You can prevent it by setting a Transfer PIN, enabling multi-factor authentication, and using a password manager.

Ques: Why do people SIM swap?

Ans: People swap sim to access financial accounts and for impersonation.

Ques: How does SIM swapping happen?

Ans: A fraudster tricks your mobile carrier into transferring your phone number to a new SIM card or eSIM.

Ques: How does SIM Swap work?

Ans: A fraudster uses various means to transfer the SIM from the victim to the SIM they have.

Ques: Is SIM swapping illegal?

Ans: Yes, SIM swapping is illegal.

Ques: How to tell if you've been SIM-swapped?

Ans: If you suddenly lose your mobile signal and receive SIM change alerts.