> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/cortex-xdr-agent/8.7/cortex-xdr-agent-for-linux/use-the-cortex-xdr-agent-for-linux.md). # Use the Cortex XDR agent for Linux After you install Cortex XDR agent for Linux, the agent operates transparently in the background as a system process. The Cortex XDR agent communicates with the server at a fixed 5-minute heartbeat interval to send status information and retrieve the latest security policy. Typically, it is not necessary to interact with the agent; however, to perform common actions, such as initiating a manual check in with Cortex XDR, you can use the command-line utility (also available for Mac and Windows) named Cytool. Cytool is available in the `/opt/traps/bin/cytool` directory and must be run as root or with root permissions. 1. Display the Cytool help. From the Linux server, run the **`cytool`** command without any arguments or with **`-h`** or **`--help`** options. ```screen root@ubuntu:~$ /opt/traps/bin/cytool Usage: cytool cytool - Support tool Options: -h --help Display help information. enum List processes protected by Cortex XDR. startup query List startup status for Cortex XDR endpoint agent(s) and daemon(s). startup Enable/Disable agent(s) and daemon(s) after reboot. runtime query List runtime status for agent(s), daemon(s) and kernel extensions. runtime Start/Stop agent(s), daemon(s) and kernel extensions immediately. persist list Display list of persistent databases. persist export Export database(s) to the file(s) in JSON format. persist import Import data into the database from the given JSON file. persist print [csv] Print database to the command prompt. log Set log level for the desired process. log collect Generate support file archive. dump Enable/Disable dump generation or restore policy settings. checkin Initiate Check In Now (send heartbeat to ESM). ``` Follow the usage guidelines to run additional Cytool commands. 2. List processes protected by the agent. Enter the **`cytool enum`** command. ```screen root@ubuntu:~$ cytool enum ----------------------------------- Cortex XDR list of protected processes: ----------------------------------- PID CMD UID 1098 /usr/sbin/cron -f 0 1131 /usr/sbin/rsyslogd -n 104 ``` To view processes for all users including those initiated by the operating system, specify the **`/a`** option.

Note

If you change the action mode for protected processes in the Exploit Security Profile in Cortex XDR, you must restart the protected processes for the security policy to be enforced on the processes and its forked processes, and only then you will see them on this list.

3. Start or stop Cortex XDR agent daemons. The agent comprises the pmd, dypd, analyzerd and lted processes. pmd is the main process and it automatically starts/stops dypd, analyzerd and lted. To start or stop all daemons, enter either the **`cytool runtime [start | stop] all`** command or the **`cytool startup [enable | disable] all`** command. The behavior of both commands changes both the current running state and the startup registration status of the daemons when the server boots. For example: ```screen root@ubuntu16:~# /opt/traps/bin/cytool runtime stop all Name PID User Status Command pmd N/A N/A STOPPED N/A analyzerd N/A N/A STOPPED N/A dypd N/A N/A STOPPED N/A lted N/A N/A STOPPED N/A root@ubuntu16:~# /opt/traps/bin/cytool runtime start all Name PID User Status Command pmd 20798 root Running /opt/traps/bin/pmd analyzerd 21027 cortexu+ Running /opt/traps/analyzerd/analyzerd 109 111 113 dypd 20999 root Running /opt/traps/bin/dypd -a -- 99 lted 20982 cortexu+ Running /opt/traps/ltee/lted -type 2 -config ltee_decryptor.json ``` 4. View the Cortex XDR agent security policy. The agent stores policy and security event information such as the list of trusted signers, local verdicts, and one-time actions in local databases in the `/opt/traps/persist/` directory. To troubleshoot policy issues and security events, you can use Cytool to import, export, and view information stored in the local database. To view a list of all local databases, use the **`cytool persist list`** command. ```screen root@ubuntu:~$ /opt/traps/bin/cytool persist list Persistent database list: post_detection.db Database of post-detection candidates agent_actions.db Database of one time actions cloud_frontend.db Database of Cloud frontend settings hashes_lru.dbLeastrecently used verdicts database cloud_reports.db Database of Cloud reports hashes.db Database of the verdicts received from WildFire esm_frontend.db Database of ESM frontend settings policy.db Policy database fvhash.db Database of blacklisted fvhashes trusted_signers.db Database of trusted signers hash_paths.db Database of file paths hash_override.db Database of hashes override (Admin exeptions) esm_reports.db Database of ESM reports security_events.db Database of security events (preventions) file_upload.db Database of files being uploaded to ESM hashes_retransmit.db Database of hashes to be retransmitted agent_settings.db Database of agent settings ``` To view the records of a database, use the **`cytool persistprint [`*****``*****`|`*****``*****`]`** command where you specify either the name of database (see the **`cytoolpersist list`** command) or the path to the database. Or, to export the records of a database to a JSON file, use the **`cytoolpersist export [`*****``*****`|`*****``*****`]`** command. For example: ```screen root@ubuntu:~$ /opt/traps/bin/cytool persist print security_events.db Database security_events: persistence::DB: /opt/traps/persist/security_events.db: Open persistence::DB: /opt/traps/persist/security_events.db: Open: IO error: lock /opt/traps/persist/security_events.db/LOCK: Resource temporarily unavailable 3c34dcc1-bc37-ffef-ed55-f5512df05884, Prevention ID: 3c34dcc1-bc37-ffef-ed55-f5512df05884 Time: 2018-05-02T10:31:51Z Timezone offset (min): 240 Module ID (CyveraComponent): 277 Module status (CyStatus): 0xC0400015 Blocked: false Source process ID: 14818 Source process terminated: true Source process command line: /root/Desktop/Linux_testers/ROP/lighttpd system 0 Source process file index: 0 Target process ID: 0 Target process terminated: false Target process command line: Target process file index: 0 User ID: 0 User name: Cortex XDR version: 7.3.0.0 OS name: Linux OS version: Red Hat Enterprise Linux Server release 6.9 (Santiago) Machine name: Saar_redhat64x64 Dump path: /opt/traps/forensics/3c34dcc1-bc37-ffef-ed55-f5512df05884/ Content version: 17-3805 IP Address: 10.200.0.55 Verdict (WildFire/Hash Control): 0 1 Files: Name: lighttpd Path: /root/Desktop/Linux_testers/ROP Size: 0 Hash: 8630c9e57ca58fb7966c80525c36f572416e0a8db617b8a43c946d4fa966a71c Version: Publisher: Quarantine ID: Signers: '' ------------------------------------------------ ---------- END Security Event Files ---------- root@ubuntu:~$ /opt/traps/bin/cytool persist export security_events.db persistence::DB: /opt/traps/persist/security_events.db: Open -rw-r--r-- 1 ubuntu root 25824 Jan 2 18:10 /home/ubuntu/traps/cytool/security_events.db_18.10.04.427_02.01.2018.json ``` To add records to the database, use the **`cytoolpersist import [`*****``*****`|`*****``*****` ]`` `` `*****``*** command where ***``*** is a JSON file. 5. Collect logs. Use the **` cytool log set_level`` `` `*****``*****` `` ``[ `*****``*****` `` ``|all] `** command to change the log level of an agent component where: * ***``*** is an integer value corresponding to the log level: * 1—Fatal * 2—Critical * 3—Error * 4—Warning * 5—Notice * 6—Information * 7—Debug * 8—Trace * ***``*** is the Cortex XDR agent component: **`trapsd`**, **`authorized`**, **`pmd`**, or **`dypd`**. Then use the **`cytool log collect`** command to collect all logs in a TGZ file. ```screen root@ubuntu:~$ /opt/traps/bin/cytool log 1 trapsd root@ubuntu:~$ /opt/traps/bin/cytool log collect -rw-r--r-- 1 root root 1651939 Dec 30 20:33 /tmp/Traps_log_2017-12-30_20-33-22/Traps_log_2017-12-30_20-33-22.tgz ``` 6. Manually initiate a check in with the server. Use the **`cytool checkin`** command to initiate the manual check-in. To verify the status of the check-in on Cortex XDR, view the **LAST SEEN** date from the additional details view of an endpoint on the **Endpoints** page. 7. Configure proxy communication.

Note

To configure system-wide proxy settings for your endpoints, follow the instructions below. You can also configure a Cortex XDR agent specific proxy.

If defined, the agent uses the proxy settings defined in the system environment in `/etc/environment`. If proxy settings are not defined, you can add the proxy server to the system environment by specifying the following setting in the `environment` file: **`https_proxy="http://`*****``*****`:`*****``*****`"`** where: * ***``*** is the IP address of the proxy server * ***``*** is the port number used for proxy communication. For example: **`https_proxy="http://10.196.20.244:8080"`** 8. View the version of the Cortex XDR agent. To view the version of the agent on the Linux server, open or read the `version.txt` file in the `/opt/traps/` directory. For example: ```screen root@ubuntu:~$ cat /opt/traps/version.txt traps_linux-6.1.0.1040 ce1707dadbbb67effb7bf08cd4edee60d9508377 ``` --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://cortex-docs.paloaltonetworks.com/cortex-xdr-agent/8.7/cortex-xdr-agent-for-linux/use-the-cortex-xdr-agent-for-linux.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.