Hyderabad: Four victims approached Hyderabad and Cyberabad police on Tuesday, complaining that they were duped of 11.2 lakh by fraudsters who circulated fake traffic challan APK (android package kit) files.One of the victims, a 35-year-old goldsmith from Ghansi Bazar, received a WhatsApp message ‘rto_echallan_.apk’ on Jan 17. Once he clicked on the link, an application got installed. Shortly afterwards, the fraudsters siphoned off 3.71 lakh from his HDFC account. The victim approched Hyderabad Cyber Crime police on Tuesday.In a similar complaint, a 31-year-old private employee from Moosapet downloaded, RTO CHALLAN.apk, by clicking a link he received through WhatsApp on Jan 5 and lost 1.84 lakh from his Axis Bank account.A 38-year-old software engineer from Gajularamaram clicked on an SMS link that claimed he owed a 500 speeding fine. After opening the link, he entered credit card details, PIN and OTP and subsequently, through multiple transactions, lost 3.96 lakh.A 38-year-old data science professional from Manikonda lost 1.76 lakh after she clicked on an RTO challan APK link sent via SMS. She also entered her credit card details and OTP on a webpage that opened through the link in the SMS.On their complaints, Hyderabad and Cyberabad cyber crime police registered four separate cases on Tuesday under Sections 318(4) (cheating) and 319(2) (cheating by personation) of the Bharatiya Nyaya Sanhita and the IT Act.Police said the fraudsters sent fake traffic challan links and, when a victim clicked on the link, it installed an APK file that provided remote access to phones, one-time passwords and enabled unauthorised money transfers.