In this detailed technical guide we’ll cover analyzing Bro security analytics with Gravwell. Bro is a passive network security sensor designed to provide a plugin friendly detection framework. There are a myriad of commercial Bro vendors and almost as many ways to format and store the output. Gravwell provides an efficient and simple interface for acquiring, storing, and querying Bro data.
DNS auditing is an integral part of any I.T. security program. Name resolutions can act as a great tip for discovering malware, command and control streams, or misbehaving employees. Acquiring DNS audit data can be difficult with some DNS servers (*cough* Windows *cough*); for this post we are going to show an extremely easy method of getting DNS audit data directly into Gravwell.
We are going to dive into Windows and show how to get logs flowing into Gravwell in under 5 minutes with the WinEvent ingester. Using the Windows queries we will audit login behavior, RDP usage, some Windows Defender, and identify when Bob from accounting is copying sensitive financial data to external storage devices. Also, Taylor Swift is involved; don't panic, just stay with me.
This Gravwell post is all about the wild world of Windows Event logging and analytics. Both Unix and Windows provide standardized central logging facilities; however, the structure and format of the stored logs are dramatically different. Syslog and most other logging systems with roots in Unix approach logging as an unstructured stream: a log entry is a string of text, no more, no less (we are going to ignore journald and its binary madness). Windows, however, logs all events in fully-formed XML and the logging system is integrated into the operating system itself. We should also note that logging in Windows is... less than ideal. If you are coming from the Unix world, throw out all your assumptions; things are different here.