Identify dangerous IP addresses using DNS-based blacklists, such as Spamhaus, Threatlog, BlockList.de, SpamCop, TornevallNET, GoogleSafeBrowsing, ProjectHoneypot, EmergingThreats and many more.
OpenRefine (formerly Google Refine) is a powerful tool for working with messy data: cleaning it; transforming it from one format into another; and extending it with web services and external data.