Pune: Cybercrooks allegedly siphoned off Rs2.75 lakh from a retired auditor (75) of Pune Municipal Corporation (PMC) by sending him an online wedding invitation card between Aug 31 and Sept 1.The elderly man lodged a complaint with the Kothrud police on Sunday. The retired auditor stated in his FIR that he was alone at home when he received a message on his messaging application from a number similar to his nephew’s cellphone number. He opened the message and saw an online wedding invitation card.An officer from Kothrud police said, “The retired auditor opened the wedding card and later went to sleep. Around midnight between Aug 31 and Sept 1, he started receiving messages from his bank stating Rs20,000, Rs40,000, Rs60,000 and other amounts had been withdrawn from his account. He had neither visited the bank nor an ATM, and realised that the money was being withdrawn from his bank account.”The next morning, he visited the bank and blocked his account. By then, the fraudsters had withdrawn Rs2.75 lakh from it.When he approached Pune cyberpolice, “A police officer checked his phone and found an .apk file downloaded on his cellphone. Inquiry revealed he had downloaded the .apk file by clicking on the wedding invitation card. It was a remote-access software link, and the complainant ended up sharing his banking credentials with the fraudsters after downloading it,” said an officer from the cyberpolice.On June 13 this year, a shopkeeper (53) from Tadiwala Road lodged a complaint with Bund Garden police, saying online fraudsters had siphoned off Rs5.3 lakh from his bank account by sending him an online wedding invitation. On May 21, cybercrooks sent .apk files to two different people and siphoned off money from their bank accounts. The Khadak and Faraskhana police registered two separate complaints against the online fraudsters. The two victims were cheated of a total of Rs8.5 lakh.An APK (Android Package Kit) file is the standard file format used by the Android operating system to distribute and install cellphone apps and games. Online fraudsters misuse .apk files to compromise their targets’ devices. Such files can give fraudsters remote access to a device, allowing them to monitor the cellphone or laptop. Once they obtain banking details, they siphon off money from the victims’ bank accounts.Pune cyber police have appealed to people not to download any file ending with .apk received through a message or a link. People can scan their cellphones and other devices for .apk files. If they find any such file on their devices, they should delete it without delay.