Shimla, May 18 -- Fraudsters allegedly used a customer's mobile phone to hack the Himachal Pradesh State Co-operative Bank server and withdrew Rs.11.55 crore, officials said on Saturday. According to the police, the money was transferred to 20 accounts. The transactions were done on May 11 and 12 but, due to May 13 being a holiday, the matter came to light on May 14 after the bank authorities received the Reserve Bank of India (RBI) transaction report. A complaint was immediately filed at Shimla Sadar police station, bank officials said. The fraudsters allegedly hacked the server through a mobile phone application of a customer, who holds an account at the bank's Hatli branch in Chamba district. The case has been transferred to the police's cybercrime branch. Deputy inspector general of police (cyber crime) Mohit Chawla said investigations were underway and a team from CERT-In -- the nodal agency for responding to cyber security cases -- would reach Shimla on Saturday and join the probe. Experts are trying to ascertain how the bank's security was breached. The bank authorities claimed the customers' money was safe and all transactions had been put on hold....