asyncrat-onenote-chain2

detections/endpoint/windows_spearphishing_attachment_connect_to_none_ms_office_domain_.yml

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+name: 'Windows Spearphishing Attachment Connect To None MS Office Domain'
+id: 1cb40e15-cffa-45cc-abbd-e35884a49766
+version: 1
+date: '2023-01-27'
+author: Teoderick Contreras, Splunk
+type: Hunting
+datamodel:
+- Endpoint
+description: this detection was designed to identifies suspicious office documents
+  that connect to a website aside from Microsoft Office Domain. This technique was seen in 
+  several malicious documents that abuses .rels xml properties of MS office to connect or download malicious files. 
+  This hunting query can a good pivot or guide to check what URL link it tries to connect, what domain, where the documents came from and 
+  how the connection happens.
+search: '`sysmon` EventCode=22 Image IN ("*\\winword.exe","*\\excel.exe","*\\powerpnt.exe","*\\mspub.exe","*\\visio.exe","*\\wordpad.exe","*\\wordview.exe","*\\onenote.exe",
+  "*\\onenotem.exe","*\\onenoteviewer.exe","*\\onenoteim.exe") 
+  AND NOT(QueryName IN ("*.office.com", "*.office.net"))
+  | stats count min(_time) as firstTime max(_time) as lastTime by Image QueryName QueryResults QueryStatus Computer
+  | `security_content_ctime(firstTime)` 
+  | `security_content_ctime(lastTime)` 
+  | `windows_spearphishing_attachment_connect_to_none_ms_office_domain_filter`'
+how_to_implement: To successfully implement this search, you need to be ingesting
+  logs with the process name, parent process, and command-line executions from your
+  endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the
+  Sysmon TA.
+known_false_positives: Windows Office document may contain legitimate url link other than MS office Domain. filter is needed
+references:
+- https://www.netskope.com/blog/asyncrat-using-fully-undetected-downloader
+- https://malpedia.caad.fkie.fraunhofer.de/details/win.asyncrat
+tags:
+  analytic_story:
+  - Spearphishing Attachments
+  - AsyncRAT
+  asset_type: Endpoint
+  cis20:
+  - CIS 3
+  - CIS 5
+  - CIS 16
+  confidence: 30
+  context:
+  - Source:Endpoint
+  - Stage:Execution
+  dataset:
+  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1566.001/office_doc_abuses_rels/sysmon.log
+  impact: 30
+  kill_chain_phases:
+  - Exploitation
+  message: a office document process $Image$ connect to an URL link $QueryName$ in $Computer$
+  mitre_attack_id:
+  - T1566.001
+  - T1566
+  nist:
+  - DE.CM
+  observable:
+  - name: Computer
+    type: Endpoint
+    role:
+    - Victim
+  product:
+  - Splunk Enterprise
+  - Splunk Enterprise Security
+  - Splunk Cloud
+  required_fields:
+  - _time
+  - Image 
+  - QueryName 
+  - QueryResults 
+  - QueryStatus 
+  - Computer
+  risk_score: 9
+  security_domain: endpoint

tests/endpoint/windows_spearphishing_attachment_connect_to_none_ms_office_domain.test.yml

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+name: Windows Spearphishing Attachment Connect To None MS Office Domain Unit Test
+tests:
+- name: 'Windows Spearphishing Attachment Connect To None MS Office Domain'
+  file: endpoint/windows_spearphishing_attachment_connect_to_none_ms_office_domain.yml
+  pass_condition: '| stats count | where count > 0'
+  earliest_time: -24h
+  latest_time: now
+  attack_data:
+  - file_name: sysmon.log
+    data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1566.001/office_doc_abuses_rels/sysmon.log
+    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
+    sourcetype: xmlwineventlog
+    update_timestamp: true