mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
Eric McGinnis
57 lines
3.5 KiB
YAML
57 lines
3.5 KiB
YAML
name: Windows Alternate DataStream - Executable Content
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id: a258bf2a-34fd-4986-8086-78f506e00206
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version: 13
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creation_date: '2024-01-10'
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modification_date: '2026-05-13'
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author: Steven Dick, 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 writing of data with an IMPHASH value to an Alternate Data Stream (ADS) in the NTFS file system. It leverages Sysmon Event ID 15 and regex to identify files with a Portable Executable (PE) structure. This activity is significant as it may indicate a threat actor staging malicious code in hidden areas for persistence or future execution. If confirmed malicious, this could allow attackers to execute hidden code, maintain persistence, or escalate privileges within the environment.
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data_source:
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- Sysmon EventID 15
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search: '`sysmon` EventCode=15 IMPHASH!=00000000000000000000000000000000 | regex TargetFilename="(?<!\/)\b\w+(\.\w+)?:\w+(\.\w+)?$" | eval file_name = replace(TargetFilename,"(.*\\\)",""), process = Image , file_path = TargetFilename, file_hash = coalesce(SHA256,SHA1,MD5,Hash) | stats count min(_time) as firstTime max(_time) as lastTime by dest dvc file_hash file_name file_path process_exec process_guid process_id process_name process_path signature signature_id user_id vendor_product Contents Image | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_alternate_datastream___executable_content_filter`'
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how_to_implement: Target environment must ingest Sysmon data, specifically Event ID 15, and import hashing/imphash must be enabled within Sysmon.
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known_false_positives: No false positives have been identified at this time.
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references:
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- https://car.mitre.org/analytics/CAR-2020-08-001/
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- https://blogs.juniper.net/en-us/threat-research/bitpaymer-ransomware-hides-behind-windows-alternate-data-streams
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- https://twitter.com/0xrawsec/status/1002478725605273600?s=21
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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: Base64 content written to an NTFS alternate data stream in $dest$, see command field for details.
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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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threat_objects:
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- field: file_hash
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type: file_hash
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- field: file_name
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type: file_name
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analytic_story:
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- Windows Defense Evasion Tactics
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asset_type: Endpoint
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mitre_attack_id:
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- T1564.004
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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/T1564.004/ads_abuse/ads_abuse_sysmon.log
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source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
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sourcetype: XmlWinEventLog
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test_type: unit
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