mirror of
https://github.com/splunk/security_content
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Bhavin Patel
82 lines
2.8 KiB
YAML
82 lines
2.8 KiB
YAML
name: Windows Alternate DataStream - Executable Content
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id: a258bf2a-34fd-4986-8086-78f506e00206
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version: 3
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date: '2024-05-30'
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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
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to an Alternate Data Stream (ADS) in the NTFS file system. It leverages Sysmon Event
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ID 15 and regex to identify files with a Portable Executable (PE) structure. This
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activity is significant as it may indicate a threat actor staging malicious code
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in hidden areas for persistence or future execution. If confirmed malicious, this
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could allow attackers to execute hidden code, maintain persistence, or escalate
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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+)?$"
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| eval file_name = replace(TargetFilename,"(.*\\\)",""), process = Image , file_path
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= TargetFilename, file_hash = coalesce(SHA256,SHA1,MD5,Hash) | stats count min(_time)
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as firstTime max(_time) as lastTime values(user) as user by dest, process, process_guid,
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file_name, file_path, file_hash, IMPHASH | `security_content_ctime(firstTime)` |
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`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
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15, and import hashing/imphash must be enabled within Sysmon.
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known_false_positives: Unknown
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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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tags:
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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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confidence: 80
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impact: 100
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message: Base64 content written to an NTFS alternate data stream by $user$, see
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command field for details.
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mitre_attack_id:
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- T1564
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- T1564.004
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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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- name: user
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type: User Name
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role:
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- Victim
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- name: file_name
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type: File Name
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role:
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- Attacker
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- name: file_hash
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type: File Hash
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role:
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- Attacker
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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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- dest
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- TargetFilename
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- Image
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- Contents
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- file_hash
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- process_guid
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- IMPHASH
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risk_score: 80
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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/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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update_timestamp: true
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