mirror of
https://github.com/splunk/security_content
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Bhavin Patel
90 lines
3.1 KiB
YAML
90 lines
3.1 KiB
YAML
name: Windows InstallUtil Uninstall Option
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id: cfa7b9ac-43f0-11ec-9b48-acde48001122
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version: 1
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date: '2021-11-12'
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author: Michael Haag, Splunk
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status: production
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type: TTP
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description: 'The following analytic identifies the Windows InstallUtil.exe binary.
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This will execute code while bypassing application control using the `/u` (uninstall)
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switch.
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InstallUtil uses the functions install and uninstall within the System.Configuration.Install
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namespace to process .net assembly. Install function requires admin privileges,
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however, uninstall function can be run as an unprivileged user.
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When `InstallUtil.exe` is used in a malicous manner, the path to an executable on
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the filesystem is typically specified. Take note of the parent process. In a suspicious
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instance, this will be spawned from a non-standard process like `Cmd.exe`, `PowerShell.exe`
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or `Explorer.exe`.
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If used by a developer, typically this will be found with multiple command-line
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switches/arguments and spawn from Visual Studio.
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During triage review resulting network connections, file modifications, and parallel
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processes. Capture any artifacts and review further.'
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data_source:
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- Sysmon Event ID 1
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search:
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selection1:
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OriginalFileName: InstallUtil.exe
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selection2:
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Image|endswith: installutil.exe
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selection3:
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CommandLine:
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- '*/u*'
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- '*uninstall*'
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condition: (selection1 or selection2) and selection3
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how_to_implement: To successfully implement this search you need to be ingesting information
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on process that include the name of the process responsible for the changes from
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your endpoints into the `Endpoint` datamodel in the `Processes` node. In addition,
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confirm the latest CIM App 4.20 or higher is installed and the latest TA for the
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endpoint product.
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known_false_positives: Limited false positives should be present. Filter as needed
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by parent process or application.
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references:
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- https://evi1cg.me/archives/AppLocker_Bypass_Techniques.html#menu_index_12
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- https://github.com/api0cradle/UltimateAppLockerByPassList/blob/master/md/Installutil.exe.md
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- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.004/T1218.004.md
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tags:
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analytic_story:
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- Signed Binary Proxy Execution InstallUtil
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- Living Off The Land
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asset_type: Endpoint
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confidence: 100
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impact: 80
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message: An instance of $parent_process_name$ spawning $process_name$ was identified
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on endpoint $dest$ by user $user$ performing an uninstall.
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mitre_attack_id:
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- T1218.004
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- T1218
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observable:
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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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- name: dest
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type: Hostname
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role:
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- Victim
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- name: parent_process_name
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type: Process
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role:
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- Parent Process
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- name: process_name
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type: Process
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role:
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- Child Process
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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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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: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1218.004/atomic_red_team/windows-sysmon.log
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source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
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sourcetype: xmlwineventlog
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