@VINNU Hadoop is a platform and framework for data storage, processing, search, etc. It provides the tools to handle massive amounts of data in a fast, scalable manner, but it does not come with native tools to handle specific use cases such as you are describing. You will have to write your own application that knows how to detect fraudulent banking activity and then utilize hadoop to run that application over your data set.
Hadoop is really just the core HDFS and Mapreduce projects for storage of data and batch processing of it. However, there is a rich ecosystem of complimentary projects around Hadoop, such as Apache Mahout, which are geared toward specific tasks. Mahout, for example is an advanced machine learning/analytics tool which can be used to build applications such as you are describing and then you run those applications in your hadoop cluster against your data, which you have loaded into HDFS.
I hope this helps somewhat
