mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
Bhavin Patel
67 lines
2.6 KiB
YAML
67 lines
2.6 KiB
YAML
name: Linux Possible Ssh Key File Creation
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id: c04ef40c-72da-11ec-8eac-acde48001122
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version: 2
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date: '2024-05-15'
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author: Teoderick Contreras, Splunk
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status: production
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type: Anomaly
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description: The following analytic detects the creation of SSH key files in the ~/.ssh/
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directory. It leverages filesystem data to identify new files in this specific path.
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This activity is significant because threat actors often create SSH keys to gain
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persistent access and escalate privileges on a compromised host. If confirmed malicious,
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this could allow attackers to remotely access the machine using the OpenSSH daemon
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service, leading to potential unauthorized control and data exfiltration.
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data_source:
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- Sysmon for Linux EventID 11
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search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
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as lastTime FROM datamodel=Endpoint.Filesystem where Filesystem.file_path IN ("*/.ssh*")
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by Filesystem.dest Filesystem.file_name Filesystem.process_guid Filesystem.file_path
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| `drop_dm_object_name(Filesystem)` | `security_content_ctime(lastTime)` | `security_content_ctime(firstTime)`
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| `linux_possible_ssh_key_file_creation_filter`'
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how_to_implement: To successfully implement this search, you need to be ingesting
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logs with the file name, file path, and process_guid executions from your endpoints.
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If you are using Sysmon, you can use the Add-on for Linux Sysmon from Splunkbase.
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known_false_positives: Administrator or network operator can create file in ~/.ssh
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folders for automation purposes. Please update the filter macros to remove false
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positives.
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references:
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- https://www.hackingarticles.in/ssh-penetration-testing-port-22/
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- https://attack.mitre.org/techniques/T1098/004/
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tags:
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analytic_story:
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- Linux Privilege Escalation
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- Linux Persistence Techniques
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- Linux Living Off The Land
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asset_type: Endpoint
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confidence: 60
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impact: 60
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message: A file $file_name$ is created in $file_path$ on $dest$
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mitre_attack_id:
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- T1098.004
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- T1098
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observable:
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- name: dest
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type: Hostname
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role:
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- Victim
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product:
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- Splunk Enterprise
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- Splunk Enterprise Security
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- Splunk Cloud
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required_fields:
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- _time
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- Filesystem.dest
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- Filesystem.file_create_time
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- Filesystem.file_name
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- Filesystem.process_guid
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- Filesystem.file_path
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risk_score: 36
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security_domain: endpoint
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tests:
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- name: True Positive Test
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attack_data:
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- data:
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https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1098.004/ssh_authorized_keys/sysmon_linux.log
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source: Syslog:Linux-Sysmon/Operational
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sourcetype: sysmon:linux
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