Indonesian mobile provider allows customers to transfer money/credit from account to account by simply sending a text/sms to number 151. Malware writers in Indonesia appreciated this chance to make some money. The sums we have traced range from 5 000 to 10 000 Indonesian rupees (0.45 0.90 USD) The goal is to transfer large quantities of small sums in the hopes that while individual users might not notice the leak, the overall sum of transfers will be significant. All 5 Trojans are written in Python and work on Symbian.”]
Source: https://securelist.com/mobile-thefts-using-malware-in-indonesia/30477/