mirror of
https://github.com/splunk/security_content
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Bhavin Patel
69 lines
2.7 KiB
YAML
69 lines
2.7 KiB
YAML
name: Mailsniper Invoke functions
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id: a36972c8-b894-11eb-9f78-acde48001122
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version: 3
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date: '2024-05-07'
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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 execution of known MailSniper PowerShell
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functions on a machine. It leverages PowerShell logs (EventCode 4104) to identify
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specific script block text associated with MailSniper activities. This behavior
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is significant as MailSniper is often used by attackers to harvest sensitive emails
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from compromised Exchange servers. If confirmed malicious, this activity could lead
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to unauthorized access to sensitive email data, credential theft, and further compromise
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of the email infrastructure.
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data_source:
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- Powershell Script Block Logging 4104
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search: '`powershell` EventCode=4104 ScriptBlockText IN ("*Invoke-GlobalO365MailSearch*",
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"*Invoke-GlobalMailSearch*", "*Invoke-SelfSearch*", "*Invoke-PasswordSprayOWA*",
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"*Invoke-PasswordSprayEWS*","*Invoke-DomainHarvestOWA*", "*Invoke-UsernameHarvestOWA*","*Invoke-OpenInboxFinder*","*Invoke-InjectGEventAPI*","*Invoke-InjectGEvent*","*Invoke-SearchGmail*",
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"*Invoke-MonitorCredSniper*", "*Invoke-AddGmailRule*","*Invoke-PasswordSprayEAS*","*Invoke-UsernameHarvestEAS*")
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| stats count min(_time) as firstTime max(_time) as lastTime by Opcode Computer
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UserID EventCode ScriptBlockText | rename Computer as dest | rename UserID as user
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| `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `mailsniper_invoke_functions_filter`'
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how_to_implement: To successfully implement this search, you need to be ingesting
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logs with the powershell logs from your endpoints. make sure you enable needed
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registry to monitor this event.
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known_false_positives: unknown
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references:
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- https://www.blackhillsinfosec.com/introducing-mailsniper-a-tool-for-searching-every-users-email-for-sensitive-data/
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tags:
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analytic_story:
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- Data Exfiltration
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asset_type: Endpoint
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confidence: 80
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impact: 90
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message: Potential mailsniper.ps1 functions executed on dest $dest$ by user $user$.
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mitre_attack_id:
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- T1114
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- T1114.001
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observable:
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- name: dest
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type: Endpoint
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role:
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- Victim
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- name: user
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type: User
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role:
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- Victim
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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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- ScriptBlockText
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- Opcode
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- Computer
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- UserID
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- EventCode
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risk_score: 72
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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/T1059.001/powershell_script_block_logging/sbl_xml.log
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source: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational
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sourcetype: xmlwineventlog
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