Script Interpreter Execution From Suspicious Folder

SIGMA detection rule by Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems) · NOASSERTION

Detects suspicious script execution from suspicious directories or folders accessible by environment variables that may indicate malware activity. Script interpreters (cscript, wscript, mshta, powershell) executing from folders like Temp, Public, or user profile directories may suggest attempts to evade detection or execute malicious scripts.

title: Script Interpreter Execution From Suspicious Folder
id: 1228c958-e64e-4e71-92ad-7d429f4138ba
status: test
description: |
    Detects suspicious script execution from suspicious directories or folders accessible by environment variables that may indicate malware activity.
    Script interpreters (cscript, wscript, mshta, powershell) executing from folders like Temp, Public, or user profile directories may suggest attempts to evade detection or execute malicious scripts.
references:
    - https://www.virustotal.com/gui/file/91ba814a86ddedc7a9d546e26f912c541205b47a853d227756ab1334ade92c3f
    - https://symantec-enterprise-blogs.security.com/blogs/threat-intelligence/shuckworm-russia-ukraine-military
    - https://learn.microsoft.com/en-us/windows/win32/shell/csidl
author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2022-02-08
modified: 2026-02-17
tags:
    - attack.execution
    - attack.t1059
logsource:
    category: process_creation
    product: windows
detection:
    selection_proc_image:
        Image|endswith:
            - '\cscript.exe'
            - '\mshta.exe'
            - '\wscript.exe'
    selection_proc_flags:
        CommandLine|contains:
            - ' -ep bypass '
            - ' -ExecutionPolicy bypass '
            - ' -w hidden '
            - '/e:javascript '
            - '/e:Jscript '
            - '/e:vbscript '
    selection_proc_original:
        OriginalFileName:
            - 'cscript.exe'
            - 'mshta.exe'
            - 'wscript.exe'
    selection_folders_1:
        CommandLine|contains:
            - ':\Perflogs\'
            - ':\Users\Public\'
            - '\%Public%'
            - '\AppData\Local\Temp'
            - '\AppData\Roaming\Temp'
            - '\Temporary Internet'
            - '\Windows\Temp'
            - '\Start Menu\Programs\Startup\'
            - '%TEMP%'
            - '%TMP%'
            - '%LocalAppData%\Temp'
    selection_folders_2:
        - CommandLine|contains|all:
              - ':\Users\'
              - '\Favorites\'
        - CommandLine|contains|all:
              - ':\Users\'
              - '\Favourites\'
        - CommandLine|contains|all:
              - ':\Users\'
              - '\Contacts\'
        - CommandLine|contains|all:
              - ':\Users\'
              - '\Documents\'
        - CommandLine|contains|all:
              - ':\Users\'
              - '\Music\'
        - CommandLine|contains|all:
              - ':\Users\'
              - '\Pictures\'
        - CommandLine|contains|all:
              - ':\Users\'
              - '\Videos\'
    filter_optional_chocolatey_installer:
        ParentImage:
            - 'C:\Windows\System32\Msiexec.exe'
            - 'C:\Windows\SysWOW64\Msiexec.exe'
        Image|endswith: '\powershell.exe'
        CommandLine|contains|all:
            - '-NoProfile -ExecutionPolicy Bypass -Command'
            - 'AppData\Local\Temp\'
            - 'Install-Chocolatey.ps1'
    condition: 1 of selection_proc_* and 1 of selection_folders_* and not 1 of filter_optional_*
falsepositives:
    - Various legitimate software have been observed to use similar techniques for installation or update purposes;thus, it is recommended to review and tune filters for your environment to reduce false positives before deploying to production.
level: high
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_susp_script_exec_from_env_folder/info.yml

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Executable code, not a declarative rule

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