DEHRADUN: A 54-year-old man allegedly lost Rs 3.6 lakh after opening an “e-RTO challan” which he received from an unidentified number on WhatsApp, police said on Thursday.The incident took place on Dec 27 last year and came to fore on Wednesday after an FIR was registered under BNS section 318 (4) and section 66 of IT Act against ‘unidentified persons’, following the victim’s complaint in the city’s Nehru Colony area.Inspector Santosh Singh Kunwar of Nehru Colony thana said, “The man received a message from an unknown number ‘RTO Challan.APK’. He opened the file under the impression that it was a challan for a traffic violation committed by him. But on opening the file, he claimed that around Rs 3.6 lakh was transferred from his bank account in several transactions before he could realise what actually happened.”“A probe has been launched to track down the culprits,” Kunwar said, adding, “We want to appeal to people against opening suspicious APK files, as they may contain malware and are sent by cyber criminals to dupe their targets.”Recently, there were instances of huge cyber scams where malicious files, disguised as e-wedding invitations on WhatsApp, had hacked into people’s phones and stole money and data.