Overview The Cyber Crime Wing of the Tamil Nadu Police has issued a public advisory concerning a new and emerging cyber fraud. This fraud involves criminals impersonating courier or delivery service agents to fraudulently access citizens’ bank accounts and social media profiles. The advisory aims to increase public awareness and prevent further victimization. Key Developments Modus Operandi The cybercriminals contact individuals under the guise of confirming or rescheduling a parcel delivery. During the conversation, victims are instructed to dial a USSD (Unstructured Supplementary Service Data) code received via SMS. This code typically begins with *21* followed by a mobile number belonging to the fraudster. Dialing this code activates call forwarding on the victim’s mobile phone without their knowledge. Impact of Call Forwarding Once call forwarding is activated, all incoming calls, including bank verification calls, OTP confirmations, and authentication calls from WhatsApp or Telegram, are automatically diverted to the fraudster. This allows criminals to carry out unauthorized financial transactions and take over messaging accounts. Official Advisory Additional Director General of Police , Cyber Crime Wing , Sandeep Mittal , has cautioned the public and appealed to them to remain alert and share this advisory with family members, friends, and colleagues. The advisory was published on December 20, 2025 . UPSC Relevance This news is relevant to GS3: Science and Technology and GS3: Security as it highlights the evolving nature of cybercrime and its potential impact on financial security. It also touches upon GS2: Government Policies related to cybersecurity and public awareness campaigns. Important Facts Tamil Nadu Police Cyber Crime Wing issued the advisory. Fraudsters impersonate courier/delivery service agents . Victims are instructed to dial a USSD code starting with *21* . Call forwarding is activated without the victim's knowledge. Fraudsters gain access to bank verification calls and OTP confirmations . Sandeep Mittal cautioned the public. Advisory published on December 20, 2025 .