Abstract: On the internet, an autonomous system is the unit of router policy which is also sometimes referred to as a routing domain. An autonomous system is assigned a globally unique number called Autonomous System Number (ASN). The investigators and network operators have recently identified that the high profile autonomous systems exhibit disproportionately high malicious behavior since they are attacked by malicious network. In this paper we explore whether some ASs are safe zone for communication through internet. We look for ISPs and ASs that exhibit disproportionately high malicious behavior using 10 popular blacklists, plus local spam data, and extensive DNS resolutions based on the contents of the blacklists. We find that some ASs have over 80% of their routable IP address space blacklisted. Overall, we conclude that examining malicious activity at AS granularity can unearth networks with lax security or those that harbor cybercrime.