Mumbai, February 23: India’s cybercrime authorities have issued an urgent warning regarding a rising "Unstructured Supplementary Service Data" (USSD) scam that allows fraudsters to hijack phone calls without installing a single piece of malware. By tricking users into dialling a code starting with 21 (*21*Phone Number#), criminals are successfully redirecting bank OTPs and private calls to their own devices. The Indian Cyber Crime Coordination Centre (I4C) under the Ministry of Home Affairs recently flagged this as a critical threat, as it enables "silent takeovers" of bank accounts and messaging apps like WhatsApp.

How the *21*Phone Number# Scam Operates

The scam relies on social engineering rather than technical hacking. A fraudster typically calls a victim posing as a courier agent (from companies like Blue Dart or Delhivery) or a telecom service provider (Airtel, Jio, or VI). Payal Gaming aka Payal Dhare Meets Sundar Pichai Months After 'Viral MMS Video' Controversy, Shares Photos.

They claim there is an "urgent issue" with a delivery or a "SIM card update" that requires immediate verification. The victim is then instructed to dial a specific sequence on their phone, such as *21*<10-digit-mobile-number>#. In the telecom world, *21* is a legitimate USSD command for unconditional call forwarding. By dialling it, the user unknowingly instructs their network provider to divert every incoming call to the scammer's number.

The Danger: Intercepting OTPs

Once call forwarding is active, the victim's phone stops ringing for incoming calls. The consequences are immediate and severe:

  • Voice OTPs: Scammers trigger "forgot password" or "verify transaction" requests for the victim's bank or UPI accounts. Since many banks use automated voice calls for OTPs, the code goes directly to the criminal.

  • Account Hijacking: Using the same method, scammers can take over WhatsApp or Telegram accounts by choosing the "Call Me" option for verification.

  • Silent Execution: Unlike suspicious links or fake apps, this method leaves no digital trail on the phone and bypasses traditional antivirus software.

Red Flags to Watch For

Authorities have identified several warning signs that your phone may be targeted or compromised:

  • Sudden Silence: Your phone stops receiving calls, or callers report that your number is "busy" or "unreachable" even when you have full bars.

  • Urgency: The caller pressures you to dial the code "within minutes" to prevent a parcel from being returned or a SIM from being blocked.

  • Suspicious Prefixes: Any request to dial codes starting with *21*, *61* (forward when unanswered), or *67* (forward when busy).

How to Stay Safe from *21*Phone Number# Code Scam

If you suspect you have already dialled such a code, you must act immediately to regain control of your communications.

Action Instruction
Check Status Dial *#21# to see if call forwarding is active and to which number.
Deactivate All Dial ##002# to instantly cancel all types of call forwarding.
Report Fraud Call the National Cybercrime Helpline at 1930 or visit cybercrime.gov.in.

Expert Tip: The "Golden Hour" is critical. Reporting the scam within the first three hours significantly increases the chances of banks freezing the stolen funds before the scammers can withdraw them.

(The above story first appeared on LatestLY on Feb 23, 2026 03:32 PM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).