The de facto inter-domain routing protocol, Border Gateway Protocol (BGP), plays a critical role in the Internet routing reliability. Invalid routes generated by misconfigurations or malicious attacks will devastate the Internet routing system. In the near future, deploying a secure BGP in the Internet to completely prevent hijacking is impossible. As a result, lots of hijacking detection systems has emerged. However, they have more or less weaknesses such as long detection delay, high false alarm rate or deploy hardness. This paper proposes Argus, an agile system to fast and accurate detect prefix hijacking.