Sigma rule: Cscript/Wscript Uncommon Script Extension Execution

Rule

Title

Cscript/Wscript Uncommon Script Extension Execution

Status

test

Level

high

Author

Nasreddine Bencherchali (Nextron Systems)

Date

2023-05-15

Modified

2023-06-19

File

rules/windows/process_creation/proc_creation_win_wscript_cscript_uncommon_extension_exec.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects Wscript/Cscript executing a file with an uncommon (i.e. non-script) extension

Log source

product

windows

category

process_creation

Detection

selection_img:
    - OriginalFileName:
          - 'wscript.exe'
          - 'cscript.exe'
    - Image|endswith:
          - '\wscript.exe'
          - '\cscript.exe'
selection_extension:
    CommandLine|contains:
        # Note: add additional potential suspicious extension
        # We could specify the "//E:" flag to avoid typos by admin. But since that's prone to blind spots via the creation of assoc it's better not to include it
        - '.csv'
        - '.dat'
        - '.doc'
        - '.gif'
        - '.jpeg'
        - '.jpg'
        - '.png'
        - '.ppt'
        - '.txt'
        - '.xls'
        - '.xml'
condition: all of selection_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.execution
• attack.t1059.005
• attack.t1059.007

MITRE ATT&CK ids this rule names

• T1059.005
• T1059.007

References

• Internal Research

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_wscript_cscript_uncommon_extension_exec.yml