mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
Eric McGinnis
67 lines
4.2 KiB
YAML
67 lines
4.2 KiB
YAML
name: Linux DD File Overwrite
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id: 9b6aae5e-8d85-11ec-b2ae-acde48001122
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version: 10
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creation_date: '2022-02-15'
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modification_date: '2026-05-13'
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author: Teoderick Contreras, Splunk
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status: production
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type: TTP
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description: The following analytic detects the use of the 'dd' command to overwrite files on a Linux system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs that include command-line details. This activity is significant because adversaries often use the 'dd' command to destroy or irreversibly overwrite files, disrupting system availability and services. If confirmed malicious, this behavior could lead to data destruction, making recovery difficult and potentially causing significant operational disruptions.
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data_source:
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- Sysmon for Linux EventID 1
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search: |-
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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
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WHERE Processes.process_name = "dd"
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AND
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Processes.process = "*of=*"
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BY Processes.action Processes.dest Processes.original_file_name
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Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
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Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
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Processes.process Processes.process_exec Processes.process_guid
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Processes.process_hash Processes.process_id Processes.process_integrity_level
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Processes.process_name Processes.process_path Processes.user
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Processes.user_id Processes.vendor_product
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| `drop_dm_object_name(Processes)`
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| `security_content_ctime(firstTime)`
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| `security_content_ctime(lastTime)`
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| `linux_dd_file_overwrite_filter`
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how_to_implement: The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
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known_false_positives: Administrator or network operator can execute this command. Please update the filter macros to remove false positives.
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references:
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- https://gtfobins.github.io/gtfobins/dd/
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- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1485/T1485.md
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drilldown_searches:
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- name: View the detection results for - "$dest$"
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search: '%original_detection_search% | search dest = "$dest$"'
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earliest_offset: $info_min_time$
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latest_offset: $info_max_time$
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- name: View risk events for the last 7 days for - "$dest$"
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search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
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earliest_offset: 7d
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latest_offset: "0"
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finding:
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title: A commandline $process$ executed on $dest$
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entity:
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field: dest
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type: system
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score: 50
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analytic_story:
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- Data Destruction
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- Industroyer2
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asset_type: Endpoint
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mitre_attack_id:
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- T1485
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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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category: endpoint
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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: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1485/linux_dd_file_overwrite/sysmon_linux.log
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source: Syslog:Linux-Sysmon/Operational
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sourcetype: sysmon:linux
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test_type: unit
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