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Redirector installation

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Marc Smeets edited this page May 22, 2023 · 11 revisions

In short

  1. extract redirs.tgz
  2. Run: install-redir.sh $FilebeatID $ScenarioName $IP/DNS:PORT
  3. Modify the logging format of your reverse proxy

In detail

Copy and extract the redirs.tgz you generated in the previous step on your redirector as part of your red team infra deployment procedures. Run: install-redir.sh $FilebeatID $ScenarioName $IP/DNS:PORT

  • $FilebeatID is the identifier of this redirector within filebeat.
  • $ScenarioName is the name of the attack scenario this redirector is used for.
  • $IP/DNS:PORT is the IP or DNS name and port where filebeat logs are shipped to, this would be the IP/DNS of your RedELK server. Even if you use the default port (TCP/5044) you need to provide this as a parameter.

This script will set install filebeat and dependencies, install the required certificates, adjust the filebeat configuration and start filebeat.

Debugging

Having issues? Check the following:

  • The installer output in redelk-install.log.
  • Filebeat errors in its log file (/var/log/filebeat or filebeat mentioned in /var/log/syslog depending on your Linux flavour used). You want to make sure it is tracking the right log files. And you want to make sure it can connect to the RedELK server. If no connection is established, this is often due to firewall issues, or due to incorrect SSL parameters given in the certs/config.cfg file.

Modify logging format

The applications used for redirection still need manual tuning in order to get the most out of them. This is done differently for Apache, Nginx and HAProxy. Details of each can be found below, and example configuration files are shipped with the RedELK package in the example-data-and-configs folder

See Naming requirements for detailed info on naming requirements.

Apache specifics

RedELK requires:

  1. Enabling of Apache specific modules. Run a2enmod rewrite proxy proxy_http proxy_connect ssl proxy_html deflate headers to do so.
  2. modification to the default Apache configuration in order to log more details. Most importantly are the 'LogFormat' and 'CustomLog' directives:
  • LogFormat "%t %{hostname}e apache[%P]: frontend:%{frontend_name}e/%A:%{local}p backend:%{backend_name}e client:%h:%{remote}p xforwardedfor:%{X-Forwarded-For}i headers:{%{User-Agent}i|%{Host}i|%{X-Forwarded-For}i|%{X-Forwarded-Proto}i|%{X-Host}i|%{Forwarded}i|%{Via}i|} statuscode:%s request:%r" redelklogformat
  • CustomLog ${APACHE_LOG_DIR}/access-redelk.log redelklogformat

An example Apache config file can be found here

By default Filebeat on the redirector will look at the log file /var/log/apache2/access-redelk.log. You can change these manually in the filebeat config file.

HAProxy specifics

RedELK requires a modification to the default HAProxy configuration in order to log more details.

In the 'defaults' section:

log-format "GMT:%T frontend:%f/%H/%fi:%fp backend:%b client:%ci:%cp xforwardedfor:%[capture.req.hdr(3)] headers:%hr statuscode:%ST request:%r"

At each relevant 'frontend' section:

 declare capture request len 40000
 capture request header User-Agent len 512
 capture request header Host len 512
 capture request header X-Forwarded-For len 512
 capture request header X-Forwarded-Proto len 512
 capture request header X-Host len 512
 capture request header Forwarded len 512
 capture request header Via len 512

By default Filebeat on the redirector will look at the log file /var/log/haproxy.log. You can change these manually in the filebeat config file.

An example HAProxy config file can be found here

Nginx specifics

RedELK requires a modification to the default Nginx configuration in order to log more details.

An example HAProxy config file can be found here

By default Filebeat on the redirector will look at the log file locations /var/log/nginx/access-redelk.log. You can change these manually in the filebeat config file.

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