Configuration

  1. Basic usage
  2. Monitoring logs using regular expressions for file names
  3. Monitoring date-based logs
  4. Reading logs from Windows Event Log
  5. Reading events from Windows Event Channel
  6. Filtering events from Windows Event Channel with queries
  7. Using environment variables
  8. Using multiple outputs

Basic usage

Log data collection is configured in the ossec.conf file primarily in the localfile, remote and global sections. Configuration of log data collection can also be completed in the agent.conf file to centralize the distribution of these configuration settings to relevant agents.

As in this basic usage example, provide the name of the file to be monitored and the format:

<localfile>
    <location>/var/log/messages</location>
    <log_format>syslog</log_format>
</localfile>

Monitoring logs using regular expressions for file names

Wazuh supports posix regular expressions. For example, to analyze every file that ends with a .log inside the /var/log directory, use the following configuration:

<localfile>
    <location>/var/log/*.log</location>
    <log_format>syslog</log_format>
</localfile>

Monitoring date-based logs

For log files that change according to the date, you can also specify a strftime format to replace the day, month, year, etc. For example, to monitor the log files like C:\Windows\app\log-08-12-15.log, where 08 is the year, 12 is the month and 15 the day (and it is rolled over every day), configuration is as follows:

<localfile>
    <location>C:\Windows\app\log-%y-%m-%d.log</location>
    <log_format>syslog</log_format>
</localfile>

Reading logs from Windows Event Log

To monitor a Windows event log, you need to provide the format as “eventlog” and the location as the name of the event log:

<localfile>
    <location>Security</location>
    <log_format>eventlog</log_format>
</localfile>

Reading events from Windows Event Channel

You can additionally monitor specific Windows event channels. The location is the name of the event channel. This is the only way to monitor the Applications and Services logs. If the file name contains a “%”, replace it with “/”:

<localfile>
    <location>Microsoft-Windows-PrintService/Operational</location>
    <log_format>eventchannel</log_format>
</localfile>

Filtering events from Windows Event Channel with queries

Events from the Windows Event channel can be filtered as below:

<localfile>
  <location>System</location>
  <log_format>eventchannel</log_format>
  <query>Event/System[EventID=7040]</query>
</localfile>

Using environment variables

Environment variables like %WinDir% can be used in the location pattern. The following is an example of reading logs from an IIS server:

<localfile>
    <location>%WinDir%\System32\LogFiles\W3SVC3\ex%y%m%d.log</location>
    <log_format>iis</log_format>
</localfile>

Using multiple outputs

Log data is sent to the agent socket by default, but it is also possible to specify other sockets as output. ossec-logcollector uses UNIX type sockets to communicate allowing TCP or UDP protocols. To add a new output socket we need to specify it using the tag <socket> as shown in the following example configuration:

<socket>
    <name>custom_socket</name>
    <location>/var/run/custom.sock</location>
    <mode>tcp</mode>
    <prefix>custom_syslog: </prefix>
</socket>

<socket>
    <name>test_socket</name>
    <location>/var/run/test.sock</location>
</socket>

Note

More information about defining a socket: socket

Once the socket is defined, it’s possible to add the destination socket for each localfile:

<localfile>
    <log_format>syslog</log_format>
    <location>/var/log/messages</location>
    <target>agent,test_socket</target>
</localfile>

<localfile>
    <log_format>syslog</log_format>
    <location>/var/log/messages</location>
    <target>custom_socket,test_socket</target>
</localfile>

Warning

To keep the output to the default socket we need to specify it using ‘agent’ as target. Otherwise the output will be redirected only to the specified targets.