Network resolution dns the fields and tags in the network resolution dns data model. Because we are using a dhcp server on all client pcs, just having ip address in the event data is no good. Initially we were going to run a reverse dns lookup against the ips to see what pointer records they had, however, we thought doing a whois lookup would be higher. To follow along with this example in your splunk deployment, download these csv files and complete the steps in the use field lookups section of the search tutorial for both the prices. Logging dns transactions from different sources such as. External lookup uses python scripts or binary executables to populate your events with field values from an external source. Choose any endpoint on your organizations network, using nslookup, perform an a record lookup for.
Dns entropy hunting and you managed splunk, customized. Classify ip addresses in splunk by any criteria relevant to your environment. If you are using malwaredomains, you can find it here. Splunk lookup helps you in adding a field from an external source based on the value that matches your field in the event data. Use dns data to identify malware patient zero splunk. Our hosted whois web service provides the registration details, also known as the whois record, of a domain name, an ip address or. Hi we are currently testing out splunk to monitor our cisco asa 5510 firewall, but running into a problem. The dnsjava library requires running on the sun jvm. If you are using a debian based server please refer to the debian note at the bottom of this document.
I have used my alert scripting to block attackers in the past such as those scanning heavily against ssh. Rightclick dns server, point to view, and then click show analytic and debug logs. When you create the lookup definition for the vendors. Apps from splunk, our partners and our community enhance and extend the power of the splunk platform. To make using whois api easier, integrate it with the platforms. In any event, heres the steps we did to run a reverse dns lookup on all the domains and permutations. For example, dns queries collected by splunk stream.
If you have the dhcp dns info also stored in splunk, you could make use of it in various ways to meet your needs. Nov 06, 2015 excellent at this point the splunk stream app will be deployed to all of your dns servers and sit idle. This wiki article will discuss a system that i created that allows the online and dynamic editing of lookup tables in the etcsystemlookups folder. This blog post is part fifteen of the hunting with splunk.
Back at splunk to work with the security research team, this is my first blog post and i would like to hear what you people have got to. You could run scheduled searches against the dhcp dns logs to append to a timebased lookup file, which can be referenced for your sourcetype to perform the lookup at search time for your other data. The lookup does not need to be defined in nf or nf for you to use this command, but lookup table you reference must be uploaded to splunk enterprise. Once you download a list, you will need to format it to fit the splunk lookup format. In this post, i will be discussing some splunk queries from the sans. Download the addon to integrate into your splunk app for microsoft exchange or windows infrastructure deployment or use it to provide dns data to your own splunk app. It can translate fields into more meaningful information at search time. By default, the dns lookup tool will return an ip address if you give it a name e. Similarly, youve probably found the process of googling how to update continue reading manually update a lookup csv in splunk. The dns lookup is done directly against the domains authoritative name server, so changes to dns records should show up instantly. Initially we were going to run a reverse dns lookup against the ips to see what pointer records they had, however, we thought doing a whois lookup would be higher integrity. If you use lookups, you have probably run into a situation where youve wanted to update a lookup file.
Dns resolution in a search question splunk answers. I just want to presumably use lookup dnslookup to have splunk query. Turn on debug mode for dns requests on your windows dns servers and send the logs to splunk. These lookup table recipes briefly show advanced solutions to common, realworld problems. We use etchosts for the ip to hostname lookup, you can also use a dns server to fill this requirement such as bind9, ms server or dnsmasq to name a few. If you have splunk cloud and want to define external lookups, file a support ticket. Using splunk can help ingest the large volume of log data and. The lookup does not need to be defined in nf or nf for you to use this command, but lookup table you reference must be. Fill in one or more commaseparated domain names or ipv4. Define an external lookup in splunk web splunk documentation. Ensure you can open the file in excel and no issues with delimiters. In the dns lookup example above, the csv table contains two fields. The report to abuseipdb for splunk app was developed and tested on splunk version 7. Splunk a dns lookup for abuse contacts lets follow up on our dns theme of the last post.
Under when maximum event log size is reached, choose do not overwrite events clear logs manually, select the enable logging checkbox, and click ok when you are asked if you. Search help the dns traffic can be collected simultaneously from many different devices. The next few steps will prepare the environment to start collections create a new index i. Excellent at this point the splunk stream app will be deployed to all of your dns servers and sit idle. Finding whats relevant and how to use the information.
Whois api splunk application tutorial platforms whois api. The windows dns response logs dont really add much context. Download free 60day trial no infrastructure, no problemaggregate, analyze and get answers from your machine data. Using splunk to detect dns tunneling sti graduate student research by steve jaworski june 1, 2016. Add field matching rules to your lookup configuration. Mar 20, 2018 ive been using splunk and dns data to find badness in networks since 2011 and i continually find new methods and approaches. Turn on debug mode for dns requests on your windows dns servers and. Network resolution dns the fields and tags in the network resolution dns data model describe dns traffic, both server. Developers can build custom splunk applications or integrate splunk data into other applications. Splunk lookup the lookup command to invoke field value lookups. Configure windows domain name server download and configure the splunk addon for windows. Dns tunneling is a method to bypass security controls and exfiltrate data from a targeted organization. Syslogng can be configured to do reverse dns lookups using the following options.
This test will list dns records for a domain in priority order. Splunk security continues to grow thanks to insight splunk enterprise offers for all data. Add context to splunk searches subnet and ip classification. This can create a metric ton of lookup requests to the dns servers your splunk server normally points at.
The steps to install this app are relatively straightforward simply download the. If youre interested in an efficient dns monitoring environment. It enriches the data while comparing different event fields. Below we will see how can we create splunk lookup step by step process to create splunk lookups.
Enriching threat feeds with whois information splunk. Manually update a lookup csv in splunk keith twombley. Great thanks to mark for allowing me access to the beta builds. How to do dns lookup for eventtime question splunk. From now on well refer to this server as indexer only, the name of splunk should not be use to designated this server e. If you use splunk, you probably use lookups to add handy data to your searches and alerts. Splunk lookup command can accept multiple event fields and destfields. Security logs, syslog, web server logs, and windows logs are just the beginning. Whois api splunk application tutorial platforms whois. Understand bucket rotation and plan for data size increases. I want to filter the search by matching ip address to subnet masks.
Solved getting dns forwarder info for multiple dns servers. Install splunk on ubuntu in 5 mins splunk is a powerful log database that can be used for the analysis of any sort of log data through its easy to use search engine. Install bro or something similar at your network edge to capture dns response traffic. Before starting, ensure that you have a dns reverse lookup zone configured for those vms where youare going to install collectd, otherwise the app with show the vms with their ip addresses instead of the fqdn. Dec 04, 2019 in this section of the splunk tutorial you will learn the lookup tables recipes, how to use reverse lookup, using a twotiered lookup, using multistep lookup, creating a lookup table from search results, and more. When available, splunk provides updates, upgrades, maintenance releases and reset keys only to splunk support customers. Logging dns transactions from different sources such as network taps and the dns servers themselves can generate large volumes of data to investigate. Rightclick dnsserver, point to view, and then click show analytic and debug logs. For instance, if a dns record is deleted from a domain controller, users might not be able to log in, and the. That traffic load can cause unforeseen issues at times.
The latest release of sysmon brings a bunch of improvements and introduces eventid 23. In versions of the splunk platform prior to version 6. Derek deals up some oldies but goodies, shows some awesome visualizations, and then brings some new slaying techniques to the adversary battle. Regardless of your organizations size and industry, splunk can give you the answers you need to solve your toughest it, security and business.
The splunk platform makes it easy to customize splunk enterprise to meet the needs of any project. The recommendation for syslog by splunk ps is to put a syslog receiver in front of splunk instead of ingesting syslog directly. Splunk provides previous releases for customers that need access to a specific version. I like to setup dnsmasq for local dns caching on my splunk search head to help reduce that load when ip lookups are repetitive. If it resolves with wkhvlwhv ip address, that endpoint is susceptible to dns tunneling. Dns lookup data normalized to the network resolution cim data model. Our hosted whois web service provides the registration details, also known as the whois record, of a domain name, an ip address or an email address. Download the free trials of our core splunk solutions and see firsthand the benefits it can bring to your organization. The following is the steps required to create an external lookup for a splunk enterprise deployment.
Regardless of your organizations size and industry, splunk can give you the answers you need to solve your toughest it, security and business challengeswith the option to deploy onpremises, in the cloud or via a hybrid approach. The fastest way to aggregate, analyze and get answers from your machine data. Download the addon to integrate into your splunk app for microsoft. Ip ranges can be designated as dmz, datacenter, vmware, serverfarm, webtier, or any other relevant keyword to help distinguish and classify a group of ip addresses during a search. This app provides the ability to perform arbitrary dns queries such as cname. Domaintools app for splunk and splunk es splunkbase.
If you use apache servicemix or apache karaf, youll need to adjust the etcperties file, to add. Use nslookup on your 2012 dns server to confirm your dns is resolving properly and you should be good to go take care to confirm that the 2012 server is using itself for dns when testing. In this section of the splunk tutorial you will learn the lookup tables recipes, how to use reverse lookup, using a twotiered lookup, using multistep lookup, creating a lookup table from search. All it requires is two advanced xml forms, sideview utils and a lookup table. Derek king, our security brother from england, has chosen to write on a subject near and dear to my. Marco that needs to contain the index and sourcetype of the external dns logs if you also want to make use of the advanced spf options. Sometimes your dns logs tell a story, you just need to listen a little more closely to be able to hear it. Below we will see how can we create splunk lookup step by step process to create. The splunk addon for microsoft windows dns version 1. This app complements the dnslookup command in splunk by adding a commands such as dnsquery which allow the ability to perform different dns query type such as cname and txt refer. You can also perform instant whois lookups from within the whois lookup page. Accidental or malicious deletion of dns records is one important cause of it service unavailability. Use the following options to customize the search to your specific needs. Splunk a dns lookup for abuse contacts george starcher.
Code issues 8 pull requests 9 actions security insights. The splunk security community is growing everyday, due to the unbelievable amount of flexibility, visibility, insight splunk enterprise offers for all data and as i have learned all data is security relevant. Splunk integration proactive threat intelligence domaintools. Dns insight takes an output of tcpdump as input, parses it and displays results as following charts and tables. Because we are using a dhcp server on all client pcs, just having ip address in the event data is no. Splunk dns lookup performance and caching with dnsmasq. Sample dns searches and dashboards splunk documentation. See install and deploy addons in the installation and upgrade manual for details on integrating enterprise security with splunk stream.