Splunk® Enterprise

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Monitor Windows event log data with Splunk Cloud

Windows generates log data during the course of its operations. The Windows Event Log service handles nearly all of this communication. It gathers log data that installed applications, services, and system processes publish and places the log data into event log channels. Programs such as Microsoft Event Viewer subscribe to these log channels to display events that have occurred on the system.

You can monitor event log channels and files that are on the local machine or you can collect logs from remote machines. The event log monitor runs once for every event log input that you define.

To monitor Windows Event Log channels in Splunk Cloud, use a Splunk universal or heavy forwarder to collect the data and forward it to your Splunk Cloud deployment. As a best practice, use the Splunk Add-on for Windows to simplify the process of getting data into Splunk Cloud. For instructions on using the Splunk Add-on for Windows to get data into Splunk Cloud, see Get Windows Data Into Splunk Cloud in the Splunk Cloud Admin Manual.

Why monitor event logs?

Windows event logs are the core metric of Windows machine operations. If there is a problem with your Windows system, the Event Log service has logged it. The Splunk platform indexing, searching, and reporting capabilities make your logs accessible.

Requirements for monitoring event logs

Activity Requirements
Monitor local event logs
  • The Splunk universal forwarder or Splunk Enterprise instance must run on Windows. See Install on Windows in the Installation Manual.
  • The Splunk universal forwarder or Splunk Enterprise instance must run as the Local System Windows user to read all local event logs.
Monitor remote event logs
  • The universal forwarder or heavy forwarder must run on the Windows machine from which you want to collect event logs.
  • The Splunk universal forwarder or heavy forwarder must run as a domain or remote user with read access to Windows Management Instrumentation (WMI) on the remote machine. See Choose the Windows user Splunk Enterprise should run as in the Installation Manual.
  • The user that the forwarder runs as must have read access to the event logs you want to collect.

Security and other considerations for collecting event log data from remote machines

You collect event log data from remote machines using a universal forwarder, a heavy forwarder, or WMI. As a best practice, use a universal forwarder to send event log data from remote machines to an indexer. See The universal forwarder in the Universal Forwarder manual for information about how to install, configure and use the forwarder to collect event log data. If you can't install a forwarder on the machine where you want to get data, you can use a WMI.

To install forwarders on your remote machines to collect event log data, install the forwarder as the Local System user on these machines. The Local System user has access to all data on the local machine, but not on remote machines.

To use WMI to get event log data from remote machines, you must ensure that your network and Splunk Enterprise instances are properly configured. Do not install Splunk software as the Local System user. The user you use to install the software determines the event logs that Splunk software has access to. See Security and remote access considerations for additional information on the requirements you must satisfy to collect remote data properly using WMI.

By default, Windows restricts access to some event logs depending on the version of Windows you run. For example, only members of the local Administrators or global Domain Admins groups can read the Security event logs by default.

How the Windows Event Log monitor interacts with Active Directory

When you set up an Event Log monitoring input for WMI, the input connects to an Active Directory (AD) domain controller to authenticate and, if necessary, performs any security ID (SID) translations before it begins to monitor the data.

The Event Log monitor uses the following logic to interact with AD after you set it up:

  1. If you specify a domain controller when you define the input with the evt_dc_name setting in the inputs.conf file, then the input uses that domain controller for AD operations.
  2. If you do not specify a domain controller, then the input does the following:
    1. The input attempts to use the local system cache to authenticate or resolve SIDs.
    2. If the monitor cannot authenticate or resolve SIDs that way, it attempts a connection to the domain controller that the machine that runs the input used to log in.
    3. If that does not work, then the input attempts to use the closest AD domain controller that has a copy of the Global Catalog.
  3. If the domain controller that you specify is not valid, or a domain controller cannot be found, then the input generates an error message.

Collect event logs from a remote Windows machine

You have two choices to collect data from a remote Windows machine:

  • Use a universal forwarder
  • Use WMI

Use a universal or heavy forwarder

You can install a universal forwarder or a heavy forwarder on the Windows machine and instruct it to collect event logs. You can do this manually or use a deployment server to manage the forwarder configuration.

  1. On the Windows machine for which you want to collect Windows Event Logs, download Splunk Enterprise or the universal forwarder software.
  2. Run the universal forwarder installation package to begin the installation process.
  3. When the installer prompts you, configure a receiving indexer.
  4. When the installer prompts you to specify inputs, enable the event log inputs by checking the Event logs checkbox.
  5. Complete the installation procedure.
  6. On the receiving indexer, use Splunk Web to search for the event log data as in the following example:

    host=<name of remote Windows machine> sourcetype=Wineventlog

For specific instructions to install the universal forwarder, see Install a Windows universal forwarder from an installer in the Forwarder Manual.

Use WMI

If you want to collect event logs remotely using WMI, you must install the universal or heavy forwarder to run as an Active Directory domain user. If the selected domain user is not a member of the Administrators or Domain Admins groups, then you must configure event log security to give the domain user access to the event logs.

To change event log security to get access to the event logs from remote machines, you must meet the following requirements:

You can use the wevtutil utility to set event log security.

  1. Download a Splunk Enterprise instance onto a Windows machine.
  2. Double-click the installer file to begin the installation.
  3. When the installer prompts you to specify a user, select Domain user.
  4. On the next installer pane, enter the domain user name and password that you want Splunk Enterprise to use when it runs.
  5. Follow the prompts to complete the installation of the software.
  6. Once the software has installed, log in to the instance.
  7. Use Splunk Web to add the remote event log input. See Configure remote event log monitoring later in this topic.

Anomalous machine names are visible in event logs on some systems

On some Windows systems, you might see some event logs with randomly-generated machine names. This is the result of those systems logging events before the user has named the system during the OS installation process.

This anomaly occurs only when you collect logs from versions of Windows remotely over WMI.

Configure local event log monitoring with Splunk Web

To get local Windows event log data, point your Splunk Enterprise instance at the Event Log service.

Go to the Add Data page

You can get there in two ways:

  • Splunk Settings
  • Splunk Home

From Splunk Settings:

  1. Click Settings > Data Inputs.
  2. Click Local event log collection.
  3. Click New to add an input.

From Splunk Home:

  1. Click the Add Data link in Splunk Home.
  2. Click Monitor to monitor Event Log data on the local Windows machine, or Forward to forward Event Log data from another Windows machine.
    Splunk Enterprise loads the Add Data - Select Source page.
  3. If you selected Forward, select or create the group of forwarders you want this input to apply to. See Forward data in this manual.
  4. Click Next.

Select the input source

  1. Select Local Event Logs
  2. In the Select Event Logs list, select the Event Log channels you want this input to monitor.
  3. Click each Event Log channel you want to monitor once.
    Splunk Enterprise moves the channel from the Available items window to the Selected items window.
  4. To deselect a channel, click its name in the Available Items window.
    Splunk Enterprise moves the channel from the Selected items window to the Available items window.
  5. To select or deselect all of the event logs, click the add all or remove all links.

    Selecting all of the channels can result in the indexing of a lot of data.

  6. Click Next.

Specify input settings

The Input Settings page lets you specify the application context, default host value, and index. All of these parameters are optional.

The Host field sets only the host field in the resulting events. It doesn't direct Splunk Enterprise to look on a specific machine on your network.

  1. Select the appropriate Application context for this input.
  2. Set the Host value. You have several choices for this setting. For more information about setting the host value, see About hosts.
  3. Set the Index that you want Splunk Enterprise to send data to. Leave the value as default, unless you defined multiple indexes to handle different types of events. In addition to indexes for user data, Splunk Enterprise has a number of utility indexes, which also appear in this dropdown box.
  4. Click Review.

Review your choices

After you specify all your input settings, you can review your selections. Splunk Enterprise lists all options you selected, including the type of monitor, the source, the source type, the application context, and the index.

  1. Review the settings.
  2. If they do not match what you want, click the left angle bracket ( < ) to go back to the previous step in the wizard. Otherwise, click Submit.

Splunk Enterprise then displays the "Success" page and begins indexing the specified Event Log channels.

Configure remote event log monitoring with Splunk Web

The process for configuring remote event log monitoring is nearly identical to the process for monitoring local event logs.

  1. Follow the instructions to get to the Add Data page. See Go to the Add Data page.
  2. Locate and select Remote Event Logs.
  3. In the Event Log collection name field, enter a unique, memorable name for this input.
  4. In the Choose logs from this host field, enter the host name or IP address of the machine that contains the Event Log channels you want to monitor.

    Selecting all of the Event Log channels can result in the indexing of a lot of data.

  5. Click the Find logs button to refresh the page with a list of available Event Log channels on the machine you entered.
  6. Click once on each Event Log channel you want to monitor.
    Splunk Enterprise moves the channel from the Available items window to the Selected items window.
  7. To deselect a channel, click its name in the Available Items window.
    Splunk Enterprise moves the channel from the Selected items window to the Available items window.
  8. To select or deselect all of the event logs, click the add all or remove all links.
  9. In the Collect the same set of logs from additional hosts field, enter the host names or IP addresses of additional machines that contain the Event Logs you selected previously. Separate multiple machines with commas.
  10. Click the green Next button.
  11. Follow the instructions to specify input settings. See Specify input settings.
  12. Follow the instructions to review your choices. See Review your choices.

Use the inputs.conf configuration file to configure event log monitoring

On either a universal or heavy forwarder, you can edit the inputs.conf configuration file to configure Windows event log monitoring.

  1. Using Notepad or a similar editor, open %SPLUNK_HOME%\etc\system\local\inputs.conf for editing. You might need to create this file if it doesn't exist.
  2. Enable Windows event log inputs by adding input stanzas that reference Event Log channels.
  3. Save the file and close it.
  4. Restart the Splunk platform.

For more information on configuring data inputs with the inputs.conf file, see Edit inputs.conf.

Specify global settings for Windows Event Log inputs

When you define Windows Event Log inputs in inputs.conf, make sure you explicitly specify global settings in the correct place.

If you specify global settings for Windows Event Log inputs, such as host, sourcetype, and so on, you can place those settings in one of the following areas:

  • Under the [WinEventLog] global stanza. This stanza is equal to the [default] stanza for other monitoring inputs. For example:
    [default]
    _meta = hf_proxy::meta_test
    
    [WinEventLog] 
    _meta = hf_proxy::meta_test
    host = WIN2K16_DC
    index = wineventlog
    
    [WinEventLog://Applications]
    disabled = 0
    
  • Under the Windows Event Log input stanza for the Event Log channel that you want to monitor. For example:
    [default]
    _meta = hf_proxy::meta_test
    
    [WinEventLog]
    host = WIN2K16_DC
    index = wineventlog
    
    [WinEventLog://Applications]
    disabled = 0
    _meta = hf_proxy::meta_test
    

You can review the defaults for a configuration file by looking at the examples in %SPLUNK_HOME%\etc\system\default or at the spec file in the Admin Manual.

Event log monitor configuration values

Windows event log (*.evt) files are in binary format. You can't monitor them like you do a normal text file. The splunkd service monitors these binary files by using the appropriate APIs to read and index the data within the files.

Splunk Enterprise uses the following stanzas in inputs.conf to monitor the default Windows event logs:

# Windows platform specific input processor.
[WinEventLog://Application]
disabled = 0 
[WinEventLog://Security]
disabled = 0 
[WinEventLog://System]
disabled = 0 

Monitor non-default Windows event logs

You can also configure Splunk Enterprise to monitor non-default Windows event logs. Before you can do this, you must import them to the Windows Event Viewer. After you import the logs, you can add them to your local copy of inputs.conf, as in the following example:

[WinEventLog://DNS Server]
disabled = 0
[WinEventLog://Directory Service]
disabled = 0
[WinEventLog://File Replication Service]
disabled = 0

Use the Full Name log property in Event Viewer to specify complex Event Log channel names properly

You can use the Full Name Event Log property in Event Viewer to ensure that you specify the correct Event Log channel in an inputs.conf stanza.

For example, to monitor the Task Scheduler application log, Microsoft-Windows-TaskScheduler-Operational, do the following steps:

  1. Open Event Viewer.
  2. Expand Applications and Services Logs > Microsoft > Windows > TaskScheduler.
  3. Right-click Operational and select Properties.
  4. In the dialog that appears, copy the text in the Full Name field.
  5. Append this text into the WinEventLog:// stanza of inputs.conf as in the following example:
    [WinEventLog://Microsoft-Windows-TaskScheduler/Operational]
    disabled = 0
    

Disable an event log stanza

To disable indexing for an event log, add disabled = 1 after its listing in the stanza in %SPLUNK_HOME%\etc\system\local\inputs.conf.

Configuration settings for monitoring Windows Event Logs

Splunk software uses the following settings in inputs.conf to monitor Event Log files:

Attribute Description Default
start_from

How to read events.

Acceptable values are oldest, meaning read logs from the oldest to the newest, and newest, meaning read logs from the newest to the oldest.

You can't set this attribute to newest while also setting the current_only attribute to 1.

oldest
current_only

How to index events.

Acceptable values are 1, where the input acquires events that arrive after the input starts for the first time, like tail -f on *nix systems, or 0, where the input gets all existing events in the log and then continues to monitor incoming events in real time.

You can't set this attribute to newest while also setting the current_only attribute to 1.

0
checkpointInterval

How frequently, in seconds, the Windows Event Log input saves a checkpoint.

Checkpoints store the eventID of acquired events to enable Splunk software to resume monitoring at the correct event after a shutdown or outage.

0
evt_resolve_ad_ds

The domain controller Splunk software uses to interact with Active Directory while indexing Windows Event Log channels. Valid only when you set the evt_resolve_ad_obj attribute to 1 and omit the evt_dc_name attribute.

Valid values are auto, meaning to use the nearest domain controller to bind to for AD object resolution, or PDC, meaning to bind to the primary domain controller for the AD site that the host is in. If you also set the evt_dc_name attribute, Splunk software ignores this attribute.

auto
evt_resolve_ad_obj

How Splunk software interacts with Active Directory while indexing Windows Event Log channels. Valid values are 1, meaning resolve Active Directory objects like Globally Unique IDentifier (GUID) and Security IDentifier (SID) objects to their canonical names for a specific Windows event log channel, and 0, meaning not to attempt any resolution.

When you set this value to 1, you can optionally specify the Domain Controller name or DNS name of the domain to bind to, which Splunk software uses to resolve the AD objects. If you don't set this value, Splunk software attempts to resolve the AD objects.

0
evt_dc_name

Which Active Directory domain controller to bind to resolve AD objects. This name can be the NetBIOS name of the domain controller, the fully-qualified DNS name of the domain controller, or an environment variable name specified as $Environment_variable.

If you set this attribute, then Splunk software ignores the evt_resolve_ad_ds attribute, which controls how the software determines the best domain controller to bind to for AD object resolution.

If you specify an environment variable, you must prepend a dollar sign ($) to the environment variable name. Splunk software uses the specified environment variable as the domain controller to connect to for AD object resolution. For example, to use the %LOGONSERVER% variable, specify evt_dc_name = $logonserver.

You can precede either format with two backslash characters. This attribute does not have a default.

N/A
evt_dns_name The fully-qualified DNS name of the domain to bind to resolve AD objects. N/A
evt_exclude_fields A list of Windows Event Log fields that the Windows Event Log input is to exclude when it ingests Windows Event Log data. When you specify this setting, the input removes both the key and value data for the fields you exclude. This setting works similar to the suppress_* settings, but unlike those settings, this setting is valid for all Windows Event Log fields, and excludes fields that you might have included in an allow list. When this collision happens, the instance logs an error. See "Create advanced filters with 'whitelist' and 'blacklist'" later in this topic for the list of Windows Event Log fields that you can exclude. N/A
suppress_text Whether to include the message text that comes with a security event. A value of 1 suppresses the message text, and a value of 0 preserves the text. 0
use_old_eventlog_api

Whether or not to read Event Log events with the Event Logging API.

This is an advanced setting. Contact Splunk Support before you change it.

If set to true, the input uses the Event Logging API instead of the Windows Event Log API to read from the Event Log on Windows Server 2008, Windows Vista, and higher installations.

false (Use the API that is specific to the OS.)
use_threads

Specifies the number of threads, in addition to the default writer thread, that can be created to filter events with the allow list/deny list regular expression.

This is an advanced setting. Contact Splunk Support before you change it.

The maximum number of threads is 15.

0
thread_wait_time_msec The interval, in milliseconds, between attempts to re-read Event Log files when a read error occurs.

This is an advanced setting. Contact Splunk Support before you change it.

5000
suppress_checkpoint

Whether or not the Event Log strictly follows the checkpointInterval setting when it saves a checkpoint.

This is an advanced setting. Contact Splunk Support before you change it.

By default, the Event Log input saves a checkpoint from between zero and checkpointInterval seconds, depending on incoming event volume.

false
suppress_sourcename

Whether or not to exclude the sourcename field from events.

This is an advanced setting. Contact Splunk Support before you change it.

When set to true, the input excludes the sourcename field from events and throughput performance (the number of events processed per second) improves.

false
suppress_keywords

Whether or not to exclude the keywords field from events.

This is an advanced setting. Contact Splunk Support before you change it.

When set to true, the input excludes the keywords field from events and throughput performance (the number of events processed per second) improves.

false
suppress_type

Whether or not to exclude the type field from events.

This is an advanced setting. Contact Splunk Support before you change it.

When set to true, the input excludes the type field from events and throughput performance (the number of events processed per second) improves.

false
suppress_task

Whether or not to exclude the task field from events.

This is an advanced setting. Contact Splunk Support before you change it.

When set to true, the input excludes the task field from events and throughput performance (the number of events processed per second) improves.

false
suppress_opcode

Whether or not to exclude the opcode field from events.

This is an advanced setting. Contact Splunk Support before you change it.

When set to true, the input excludes the opcode field from events and throughput performance (the number of events processed per second) improves.

false
whitelist

Whether to index events that match the specified text string. This attribute is optional.

You can specify one of two formats:

  • One or more Event Log event codes or event IDs (Event Code/ID format.)
  • One or more sets of keys and regular expressions (Advanced filtering format.)

You cannot mix formats in a single entry. You also cannot mix formats in the same stanza.

Allow lists are processed first, then deny lists. If no allow list is present, the Splunk platform indexes all events.

When you use the Event Code/ID format:

  • For multiple codes/IDs, separate the list with commas.
  • For ranges, use hyphens (for example "0-1000,5000-1000").

When using the advanced filtering format:

  • Use = between the key and the regular expression that represents your filter (for example whitelist = EventCode=%^1([8-9])$%
  • You can have multiple key/regular expression sets in a single advanced filtering entry. The Splunk platform conjuncts the sets logically. This means that the entry is valid only if all of the sets in the entry are true.
  • You can specify up to 10 whitelists per stanza by adding a number to the end of the whitelist attribute, for example whitelist1...whitelist9.
N/A
blacklist

Do not index events that match the text string specified. This attribute is optional.

You can specify one of two formats:

  • One or more Event Log event codes or event IDs (Event Log code/ID format.)
  • One or more sets of keys and regular expressions. (Advanced filtering format.)

You cannot mix formats in a single entry. You also cannot mix formats in the same stanza.

Allow lists are processed first, then deny lists. If no deny list is present, the Splunk platform indexes all events.

When using the Event Log code/ID format:

  • For multiple codes/IDs, separate the list with commas.
  • For ranges, use hyphens (for example 0-1000,5000-1000).

When using the advanced filtering format:

  • Use = between the key and the regular expression that represents your filter (for example blacklist = EventCode=%^1([8-9])$%
  • You can have multiple key/regular expression sets in a single advanced filtering entry. The Splunk platform conjuncts the sets logically. This means that the entry is valid only if all of the sets in the entry are true.
  • You can specify up to 10 deny lists per stanza by adding a number to the end of the blacklist attribute, for example blacklist1...blacklist9.
renderXml Render event data as XML supplied by the Windows Event Log subsystem. This setting is optional.

A value of 1 or true means to render the events as XML. A value of 0 or false means to render the events as plain text.

If you set renderXml to true, if you want to also create allow lists or deny lists to filter event data, you must use the $XmlRegex special key in your allow lists or deny lists.

0 (false)
index The index that this input is to send the data to. the default index
disabled

Whether or not the input is to run.

Valid values are 0, meaning that the input is to run, and 1, meaning that the input is to not run.

0

Use the Security event log to monitor changes to files

You can monitor changes to files on your system by enabling security auditing on a set of files or directories and then monitoring the Security event log channel for change events. The event log monitoring input includes three attributes which you can use in inputs.conf. For example:

[WinEventLog://Security]
disabled = 0
start_from = oldest
current_only = 0
evt_resolve_ad_obj = 1
checkpointInterval = 5
# only index events with these event IDs.
whitelist = 0-2000,3001-10000
# exclude these event IDs from being indexed.
blacklist = 2001-3000

To enable security auditing for a set of files or directories, read Auditing Security Events How To on MS Technet at http://technet.microsoft.com/en-us/library/cc727935%28v=ws.10%29.aspx.

You can also use the suppress_text attribute to include or exclude the message text that comes with a security event.

When you set suppress_text to 1 in a Windows Event Log Security stanza, the entire message text does not get indexed, including any contextual information about the security event. If you need this contextual information, do not set suppress_text in the stanza.

See the following example to include or exclude message text:

[WinEventLog://Security]
disabled = 0
start_from = oldest
current_only = 0
evt_resolve_ad_obj = 1
checkpointInterval = 5
# suppress message text, we only want the event number.
suppress_text = 1
# only index events with these event IDs.
whitelist = 0-2000,2001-10000
# exclude these event IDs from being indexed.
blacklist = 2001-3000

To use a specific domain controller, set the evt_dc_name attribute:

[WinEventLog://Security]
disabled = 0
start_from = oldest
current_only = 0
evt_resolve_ad_obj = 1
evt_dc_name = boston-dc1.contoso.com
checkpointInterval = 5
# suppress message text, we only want the event number.
suppress_text = 1
# only index events with these event IDs.
whitelist = 0-2000,2001-10000
# exclude these event IDs from being indexed.
blacklist = 2001-3000

To use the primary domain controller to resolve AD objects, set the evt_resolve_ad_ds attribute to PDC. Otherwise, it locates the nearest domain controller.

[WinEventLog://Security]
disabled = 0
start_from = oldest
current_only = 0
evt_resolve_ad_obj = 1
evt_resolve_ad_ds = PDC
checkpointInterval = 5
# suppress message text, we only want the event number.
suppress_text = 1
# only index events with these event IDs.
whitelist = 0-2000,2001-10000
# exclude these event IDs from being indexed.
blacklist = 2001-3000

Create advanced filters with whitelist and blacklist

You can perform advanced filtering of incoming events with the whitelist and blacklist settings in addition to filtering based solely on event codes. To do this, specify the key/regular expression format in the setting:

whitelist = key=<regular expression> [key=<regular expression>] ...

In this format, key must be a valid entry from the following table:

Key Description
$TimeGenerated The time that the computer generated the event. Splunk Enterprise only generates the time string as the event.
$Timestamp The time that the event was received and recorded by the Event Log service. Splunk Enterprise only generates the time string as the event.
$XmlRegex A special key that configures Splunk Enterprise to filter on XML events. To use this key, set it to the value that you want Splunk Enterprise to filter on. You must configure the input for which to apply a deny list or allow list to render events in XML. To generate XML events, specify the renderXml = true setting under the input stanza. Splunk Enterprise conjuncts multiple entries in a single allow list or deny list line. All of the filter entries must match for the filter to trigger.
Category The category number for a specific event source.
CategoryString A string translation of the category. The translation depends on the event source.
ComputerName The name of the computer that generated the event.
EventCode The event ID number for an event. Corresponds to Event ID in Event Viewer.
EventType A numeric value that represents one of the five types of events that can be logged: Error, Warning, Information, Success Audit, and Failure Audit. Available only on machines that run Windows Server 2003 and lower or clients running Windows XP and lower. See Win32_NTLogEvent class (Windows) on MSDN at http://msdn.microsoft.com/en-us/library/aa394226(v=vs.85).aspx.
Keywords An element used to classify different types of events within an event log channel. The Security Event Log channel has this element, for example.
LogName The name of the Event Log channel that received the event. Corresponds to Log Name in Event Viewer.
Message The text of the message in the event.
OpCode The severity level of the event. Corresponds to OpCode in Event Viewer.
RecordNumber The Windows Event Log record number. Each event on a Windows machine gets a record number. This number starts at 0 with the first event generated on the system, and increases with each new event generated, until it reaches a maximum of 4294967295. It then rolls back over to 0.
Sid The Security Identifier (SID) of the principal, such as a user, group, computer, or other entity, that was associated with or generated the event. See Win32_UserAccount class on MSDN at http://msdn.microsoft.com/en-us/library/windows/desktop/aa394507%28v=vs.85%29.aspx.
SidType A numeric value that represents the type of SID that was associated with the event. See Win32_UserAccount class on MSDN at http://msdn.microsoft.com/en-us/library/windows/desktop/aa394507%28v=vs.85%29.aspx.
SourceName The source of the entity that generated the event. Corresponds to Source in Event Viewer.
TaskCategory The task category of the event. Event sources let you define categories so that you can filter them with Event Viewer using the Task Category field. See Event Categories (Windows) on MSDN at http://msdn.microsoft.com/en-us/library/aa363649%28VS.85%29.aspx.
Type A numeric value that represents one of the five types of events that can be logged: Error, Warning, Information, Success Audit, and Failure Audit. Only available on machines that run Windows Server 2008 or higher, or Windows Vista or higher. See Win32_NTLogEvent class (Windows) on MSDN at http://msdn.microsoft.com/en-us/library/aa394226(v=vs.85).aspx.
User The user associated with the event. Correlates to User in Event Viewer.

<regular expression> is any valid regular expression that represents the filters that you want to include, when used with the whitelist attribute, or exclude, when used with the blacklist attribute.

You can specify more than one key/regular expression set on a single entry line. When you do this, Splunk Enterprise logically conjuncts the sets. This means that only events that satisfy all of the sets on the line are valid for inclusion or exclusion. See the following example:

whitelist = EventCode="^1([0-5])$" Message="^Error"

means to include events that have an EventCode ranging from 10 to 15 and contain a Message that begins with the word Error.

You can specify up to 10 separate allow list or deny list entries in each stanza. To do so, add a number at the end of the whitelist or blacklist entry on a separate line:

whitelist = key=<regular expression>
whitelist1 = key=<regular expression> key2=<regular expression 2>
whitelist2 = key=<regular expression>

You cannot specify an entry that has more than one key/regular expression set that references the same key. If, for example, you specify:

whitelist = EventCode="^1([0-5])$" EventCode="^2([0-5])$"

Splunk Enterprise ignores the first set and only attempts to include events that match the second set. In this case, only events that contain an EventCode between 20 and 25 match. Events that contain an EventCode between 10 and 15 do not match. Only the last set in the entry ever matches. To resolve this problem, specify two separate entries in the stanza:

whitelist = EventCode="^1([0-5])$"
whitelist1 = EventCode="^2([0-5])$"

Suppress fields from Windows Event Log events

There are two options to limit the ingestion of data by removing Windows Event Log fields from events that a Splunk Platform instance ingests:

  • Use the suppress_* settings in inputs.conf to remove certain Windows Event Log fields from ingested events.
  • Use the evt_exclude_fields setting, which lets you remove any Windows Event Log field from a Windows Event Log event. This setting removes both the excluded key and value from the event, and excludes events even if the field exists in an allow list.

You define both of these settings in the inputs.conf configuration file, under a Windows Event Log monitoring input, for example:

suppress_* example (suppresses the message text)

	
[WinEventLog://System] 
disabled=0 
suppress_text=1

evt_exclude_fields example

[WinEventLog://System] 
disabled=0 
evt_exclude_fields=EventCode,RecordNumber

See the list of fields in "Create advanced filters with 'whitelist' and 'blacklist'" earlier in this topic. See "Configuration settings for monitoring Windows Event Logs", also earlier in this topic, for more information about the settings.

Resolve Active Directory objects in event log files

To specify whether Active Directory objects like globally unique identifiers (GUIDs) and security identifiers (SIDs) are resolved for a given Windows event log channel, use the evt_resolve_ad_obj attribute (1=enabled, 0=disabled) for that channel's stanza in your local copy of inputs.conf. The evt_resolve_ad_obj attribute is on by default for the Security channel.

For example:

[WinEventLog://Security]
disabled = 0
start_from = oldest
current_only = 0
evt_resolve_ad_obj = 1
checkpointInterval = 5

To specify a domain controller for the domain that the Splunk platform instance is to bind to in order to resolve AD objects, use the evt_dc_name attribute.

The string specified in the evt_dc_name attribute can represent either the domain controller NetBIOS name, or its fully-qualified domain name (FQDN). Either name type can, optionally, be preceded by two backslash characters.

The following examples are correctly formatted domain controller names:

  • FTW-DC-01
  • \\FTW-DC-01
  • FTW-DC-01.splunk.com
  • \\FTW-DC-01.splunk.com

To specify the FQDN of the domain to bind to, use the evt_dns_name attribute.

For example:

[WinEventLog://Security]
disabled = 0
start_from = oldest
current_only = 0
evt_resolve_ad_obj = 1
evt_dc_name = ftw-dc-01.splunk.com
evt_dns_name = splunk.com
checkpointInterval = 5

When you use the evt_resolve_ad_obj and evt_dc_name attributes, the following constraints apply:

  • Splunk software first attempts to resolve SIDs and GUIDs using the domain controller (DC) specified in the evt_dc_name attribute first. If it cannot resolve SIDs using this DC, it attempts to bind to the default DC to perform the translation.
  • If Splunk software cannot contact a DC to translate SIDs, it attempts to use the local machine for translation.
  • If none of these methods works, then Splunk prints the SID as it was captured in the event.
  • Splunk software cannot translate SIDs that are not in the format S-1-N-NN-NNNNNNNNNN-NNNNNNNNNN-NNNNNNNNNN-NNNN.

If you discover that SIDs are not being translated properly, review %SPLUNK_HOME%\var\log\splunkd.log for clues about what the problem might be.

Specify whether to start index at the earliest or the most recent event

Use the start_from attribute to specify whether events are indexed starting at the earliest event or the most recent. By default, indexing starts with the oldest data and moves forward. Do not change this setting, because Splunk software stops indexing after it has indexed the backlog using this method.

Use the current_only attribute to specify whether to index all preexisting events in a given log channel. When set to 1, only events that appear from the moment the Splunk deployment was started are indexed. When set to 0, all events are indexed.

For example:

[WinEventLog://Application]
disabled = 0
start_from = oldest
current_only = 1

Display Windows Event Log events in XML

To have Splunk Enterprise generate Windows Event Log events in XML, use the renderXml setting in a Windows Event Log input stanza:

[WinEventLog://System]
 disabled = 0
 renderXml = 1
 evt_resolve_ad_obj = 1
 evt_dns_name = \"SV5DC02\"

This input stanza generates events like the following:

 
 <Event xmlns='http://schemas.microsoft.com/win/2004/08/events/event'>
   <System>
     <Provider Name='Service Control Manager' Guid='{555908d1-a6d7-4695-8e1e-26931d2012f4}' EventSourceName='Service Control Manager'/>
     <EventID Qualifiers='16384'>7036</EventID>
     <Version>0</Version>
     <Level>4</Level>
     <Task>0</Task>
     <Opcode>0</Opcode>
     <Keywords>0x8080000000000000</Keywords>
     <TimeCreated SystemTime='2014-04-24T18:38:37.868683300Z'/>
     <EventRecordID>412598</EventRecordID>
     <Correlation/>
     <Execution ProcessID='192' ThreadID='210980'/>
     <Channel>System</Channel>
     <Computer>SplunkDoc.splunk-docs.local</Computer>
     <Security/>
   </System>
   <EventData>
     <Data Name='param1'>Application Experience</Data>
     <Data Name='param2'>stopped</Data>
     <Binary>410065004C006F006F006B00750070005300760063002F0031000000</Binary>
   </EventData>
 </Event>

When you instruct Splunk Enterprise to render events in XML, event keys within the XML event render in English regardless of the machine system locale. Compare the following events generated on a French version of Windows Server.

Standard event:

04/29/2014 02:50:23 PM
LogName=Security
SourceName=Microsoft Windows security auditing.
EventCode=4672
EventType=0
Type=Information
ComputerName=sacreblue
TaskCategory=Ouverture de session spéciale
OpCode=Informations
RecordNumber=2746
Keywords=Succès de l'audit
Message=Privilèges spéciaux attribués à la nouvelle ouverture de session.
 
Sujet :
               ID de sécurité :                  AUTORITE NT\Système
               Nom du compte :                            Système
               Domaine du compte :                     AUTORITE NT
               ID d'ouverture de session :                           0x3e7
 
Privilèges :                          SeAssignPrimaryTokenPrivilege
                                             SeTcbPrivilege
                                             SeSecurityPrivilege
                                             SeTakeOwnershipPrivilege
                                             SeLoadDriverPrivilege
                                             SeBackupPrivilege
                                             SeRestorePrivilege
                                             SeDebugPrivilege
                                             SeAuditPrivilege
                                             SeSystemEnvironmentPrivilege
                                             SeImpersonatePrivilege

XML event:

<Event xmlns='http://schemas.microsoft.com/win/2004/08/events/event'>
               <System><Provider Name='Microsoft-Windows-Security-Auditing' Guid='{54849625-5478-4994-A5BA-3E3B0328C30D}'/>
                              <EventID>4672</EventID>
                              <Version>0</Version>
                              <Level>0</Level>
                              <Task>12548</Task>
                              <Opcode>0</Opcode>
                              <Keywords>0x8020000000000000</Keywords>
                              <TimeCreated SystemTime='2014-04-29T22:15:03.280843700Z'/>
                              <EventRecordID>2756</EventRecordID>
                              <Correlation/><Execution ProcessID='540' ThreadID='372'/>
                              <Channel>Security</Channel>
                              <Computer>sacreblue</Computer>
                              <Security/>
               </System>
               <EventData>
                              <Data Name='SubjectUserSid'>AUTORITE NT\Système</Data>
                              <Data Name='SubjectUserName'>Système</Data>
                              <Data Name='SubjectDomainName'>AUTORITE NT</Data>
                              <Data Name='SubjectLogonId'>0x3e7</Data>
                              <Data Name='PrivilegeList'>SeAssignPrimaryTokenPrivilege
                                             SeTcbPrivilege
                                             SeSecurityPrivilege
                                             SeTakeOwnershipPrivilege
                                             SeLoadDriverPrivilege
                                             SeBackupPrivilege
                                             SeRestorePrivilege
                                             SeDebugPrivilege
                                             SeAuditPrivilege
                                             SeSystemEnvironmentPrivilege
                                             SeImpersonatePrivilege</Data>
               </EventData>
</Event>

The Data Name keys in the XML event render in English despite rendering in the system's native language in the standard event.

Use allow lists and deny lists to filter on XML-based events

If you render events in XML, and you want to use allow lists and deny lists to filter on those events, you must use the special key $XmlRegex when you build your allow lists or deny lists.

The allow list or deny list triggers when Splunk Enterprise finds the value that you specify with $XmlRegex anywhere in the XML-rendered event. $XmlRegex doesn't work if you don't explicitly specify the input to render events in XML with the renderXml = true setting.

The $XmlRegex setting doesn't search for key-value pairs. It configures Splunk Enterprise to expect incoming events in XML format.

The following example configures the whitelist setting to allow XML events. Splunk Enterprise indexes all XML events that contain the word "Error":

[WinEventLog://System]
 disabled = 0
 renderXml = 1
 evt_resolve_ad_obj = 1
 evt_dns_name = \"SV5DC02\"
 whitelist = $XmlRegex='Error'

See the Create advanced filters with whitelist and blacklist section earlier in this topic for additional information and syntax.

Use the CLI to configure event log monitoring

You can use the CLI to configure local event log monitoring. Before you use the CLI, create stanza entries in inputs.conf first. See Use inputs.conf to configure event log monitoring in this topic.

The CLI is not available for remote Event Log collections.

To list all configured Event Log channels on the local machine, enter the following:

> splunk list eventlog

You can also list a specific channel by specifying its name as in the following example:

> splunk list eventlog <ChannelName>

To enable an Event Log channel, enter the following:

> splunk enable eventlog <ChannelName>

To disable a channel, enter the following:

> splunk disable eventlog <ChannelName>

Index exported event log files

To index exported Windows event log (.evt or .evtx) files, monitor the directory that contains the exported files. See Monitor files and directories.

Do not attempt to monitor an .evt or .evtx file that is open for writing. Windows does not allow read access to these files. Use the event log monitoring feature instead.

Constraints for monitoring Windows Event log files directly

Directly monitoring Windows Event log files have the following constraints:

  • As a result of API and log channel processing constraints on Windows XP and Server 2003 systems, imported .evt files from those systems do not contain the Message field. This means that the contents of the Message field do not appear in your index.
  • Splunk Enterprise on Windows XP and Windows Server 2003/2003 R2 cannot index .evtx files that come from systems running Windows Vista and higher or Windows Server 2008/2008 R2 and higher.
  • Splunk Enterprise on Windows Vista and higher and Server 2008/2008 R2 and higher can index both .evt and .evtx files.
  • If your .evt or .evtx file is not from a standard event log channel, you must make sure that any dynamic link library (DLL) files required by that channel are present on the computer on which you are indexing.
  • Splunk Enterprise indexes an .evt or .evtx file in the primary locale and language of the computer that collects the file.
  • Files that you export from another machine do not work with the Splunk Web Upload feature. This is because those files contain information that is specific to the machine that generated them. Other machines cannot process the files in their unaltered form.

When producing .evt or .evtx files on one system, and monitoring them on another, it's possible that not all of the fields in each event expand as they would on the system producing the events. This is caused by variations in DLL versions, availability, and APIs. Differences in OS version, language, Service Pack level, and installed third-party DLLs can also have this effect.

Last modified on 31 March, 2021
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This documentation applies to the following versions of Splunk® Enterprise: 8.1.0, 8.1.1, 8.1.2, 8.1.3, 8.1.4, 8.2.0


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