brute-ratel-2

detections/endpoint/windows_gather_victim_identity_sam_info.yml

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+name: Windows Gather Victim Identity SAM Info
+id: a18e85d7-8b98-4399-820c-d46a1ca3516f
+version: 1
+date: '2022-08-24'
+author: Teoderick Contreras, Splunk
+type: Hunting
+datamodel:
+- Endpoint
+description: The following analytic identifies a process that loads the samlib.dll module. 
+  This module is being abused by adversaries, threat actors and red teamers to access information of SAM objects or access credentials information in DC. 
+  This hunting query can be a good indicator that a process is capable of accessing the SAM object.
+search: '`sysmon` EventCode=7  ImageLoaded = "*\\samlib.dll" AND OriginalFileName = "samlib.dll" AND NOT (Image IN("C:\\Windows\\*", "C:\\Program File*", "%systemroot%\\*"))
+  | stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded process_name Computer EventCode Signed ProcessId 
+  | `security_content_ctime(firstTime)` 
+  | `security_content_ctime(lastTime)` 
+  | `windows_gather_victim_identity_sam_info_filter`'
+how_to_implement: The latest Sysmon TA 3.0 https://splunkbase.splunk.com/app/5709 will 
+  add the ImageLoaded name to the process_name field, allowing this query to work. Use as an example and implement for other products.
+known_false_positives: this module can be loaded by a third party application. Filter is needed.
+references:
+- https://redcanary.com/blog/active-breach-evading-defenses/
+- https://strontic.github.io/xcyclopedia/library/samlib.dll-0BDF6351009F6EBA5BA7E886F23263B1.html
+tags:
+  analytic_story:
+  - Brute Ratel C4
+  asset_type: Endpoint
+  cis20:
+  - CIS 3
+  - CIS 5
+  - CIS 16
+  confidence: 30
+  context:
+  - Source:Endpoint
+  - Stage:Persistence
+  - Stage:Privilege Escalation
+  - Stage:Defense Evasion
+  dataset:
+  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/brute_ratel/loading_samlib/sysmon.log
+  impact: 30
+  kill_chain_phases:
+  - Exploitation
+  message: An instance of $Computer$ that loads $ImageLoaded$ that are related to accessing to SAM object information.
+  mitre_attack_id:
+  - T1589.001
+  - T1589
+  nist:
+  - DE.CM
+  observable:
+  - name: Computer
+    type: Endpoint
+    role:
+    - Victim
+  product:
+  - Splunk Enterprise
+  - Splunk Enterprise Security
+  - Splunk Cloud
+  required_fields:
+  - _time
+  - Image 
+  - ImageLoaded 
+  - Computer 
+  - EventCode 
+  - Signed 
+  - ProcessId 
+  risk_score: 6
+  security_domain: endpoint

detections/endpoint/windows_input_capture_using_credential_ui_dll.yml

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+name: Windows Input Capture Using Credential UI Dll
+id: 406c21d6-6c75-4e9f-9ca9-48049a1dd90e
+version: 1
+date: '2022-08-24'
+author: Teoderick Contreras, Splunk
+type: Hunting
+datamodel:
+- Endpoint
+description: The following analytic identifies a process that loads the credui.dll module. 
+  This legitimate module is typically abused by adversaries, threat actors and red teamers to create a credential UI prompt 
+  dialog box to lure users for possible credential theft or can be used to dump the credentials of a targeted host. 
+  This hunting query is a good pivot to check why the process loaded this dll and if it is a legitimate file. 
+  This hunting query may hit false positive for a third party application that uses a credential login UI for user login.
+search: '`sysmon` EventCode=7  (ImageLoaded = "*\\credui.dll" AND OriginalFileName = "credui.dll") OR (ImageLoaded = "*\\wincredui.dll" AND OriginalFileName = "wincredui.dll")
+  AND NOT(Image IN("*\\windows\\explorer.exe", "*\\windows\\system32\\*", "*\\windows\\sysWow64\\*", "*:\\program files*"))
+  | stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded OriginalFileName Computer EventCode Signed ProcessId ProcessGuid
+  | `security_content_ctime(firstTime)` 
+  | `security_content_ctime(lastTime)`
+  | `windows_input_capture_using_credential_ui_dll_filter`'
+how_to_implement: The latest Sysmon TA 3.0 https://splunkbase.splunk.com/app/5709 will 
+  add the ImageLoaded name to the process_name field, allowing this query to work. Use as an example and implement for other products.
+known_false_positives: this module can be loaded by a third party application. Filter is needed.
+references:
+- https://docs.microsoft.com/en-us/windows/win32/api/wincred/nf-wincred-creduipromptforcredentialsa
+- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1056.002/T1056.002.md#atomic-test-2---powershell---prompt-user-for-password
+tags:
+  analytic_story:
+  - Brute Ratel C4
+  asset_type: Endpoint
+  cis20:
+  - CIS 3
+  - CIS 5
+  - CIS 16
+  confidence: 30
+  context:
+  - Source:Endpoint
+  - Stage:Persistence
+  - Stage:Privilege Escalation
+  - Stage:Defense Evasion
+  dataset:
+  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/brute_ratel/iso_version_dll_campaign/sysmon.log
+  impact: 30
+  kill_chain_phases:
+  - Exploitation
+  message: a process $Image$ loaded $ImageLoaded$ in $Computer$
+  mitre_attack_id:
+  - T1056.002
+  - T1056
+  nist:
+  - DE.CM
+  observable:
+  - name: Computer
+    type: Endpoint
+    role:
+    - Victim
+  product:
+  - Splunk Enterprise
+  - Splunk Enterprise Security
+  - Splunk Cloud
+  required_fields:
+  - _time
+  - Image
+  - ImageLoaded
+  - process_name
+  - Computer
+  - EventCode
+  - Signed
+  - ProcessId 
+  risk_score: 6
+  security_domain: endpoint

tests/endpoint/windows_gather_victim_identity_sam_info.test.yml

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+name: Windows Gather Victim Identity SAM Info Unit Test
+tests:
+- name: Windows Gather Victim Identity SAM Info
+  file: endpoint/windows_gather_victim_identity_sam_info.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/malware/brute_ratel/loading_samlib/sysmon.log
+    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
+    sourcetype: xmlwineventlog
+    update_timestamp: true

tests/endpoint/windows_input_capture_using_credential_ui_dll.test.yml

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+name: Windows Input Capture Using Credential UI Dll Unit Test
+tests:
+- name: Windows Input Capture Using Credential UI Dll
+  file: endpoint/windows_input_capture_using_credential_ui_dll.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/malware/brute_ratel/iso_version_dll_campaign/sysmon.log
+    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
+    sourcetype: xmlwineventlog
+    update_timestamp: true