Sigma rule: Potential SharePoint ToolShell CVE-2025-53770 Exploitation Indicators

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-47f57fc454bb, updated 2025-07-21T00:00:00.000Z.

Rule

Title
Potential SharePoint ToolShell CVE-2025-53770 Exploitation Indicators
Status
experimental
Level
high
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Date
2025-07-21
File
rules-emerging-threats/2025/Exploits/CVE-2025-53770/proc_creation_win_exploit_cve_2025_53770_indicators.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects potential exploitation of CVE-2025-53770 by identifying indicators such as suspicious command lines discovered in Post-Exploitation activities.
CVE-2025-53770 is a zero-day vulnerability in SharePoint that allows remote code execution.

Log source

product
windows
category
process_creation

Detection

selection_img:
    ParentImage|endswith: '\w3wp.exe'
selection_encoded_aspx:
    - CommandLine|wide|base64offset|contains: 'spinstall0.aspx'
    - CommandLine|base64|contains: 'spinstall0.aspx'
selection_encoded_path:
    CommandLine|wide|base64offset|contains:
        - ':\PROGRA~1\COMMON~1\MICROS~1\WEBSER~1\15\TEMPLATE\LAYOUTS'
        - ':\PROGRA~1\COMMON~1\MICROS~1\WEBSER~1\16\TEMPLATE\LAYOUTS'
        - ':\Program Files\Common Files\Microsoft Shared\Web Server Extensions\15\TEMPLATE\LAYOUTS'
        - ':\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\TEMPLATE\LAYOUTS'
selection_ioc:
    CommandLine|contains:
        - '-EncodedCommand JABiAGEAcwBlADYANABTAHQAcgBpAG4AZwAgAD0'
        - 'TEMPLATE\LAYOUTS\spinstall0.aspx'
condition: (selection_img and 1 of selection_encoded_*) or selection_ioc

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.initial-access
  • attack.t1190
  • cve.2025-53770
  • detection.emerging-threats

CVEs this rule names

MITRE ATT&CK ids this rule names

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2025/Exploits/CVE-2025-53770/proc_creation_win_exploit_cve_2025_53770_indicators.yml

Sources and licences

  • SigmaHQ

    "Potential SharePoint ToolShell CVE-2025-53770 Exploitation Indicators" by Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2025/Exploits/CVE-2025-53770/proc_creation_win_exploit_cve_2025_53770_indicators.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Potential SharePoint ToolShell CVE-2025-53770 Exploitation Indicators",
entity page, dataset version ref-47f57fc454bb, updated 2025-07-21T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/7477881c-ec3b-49d6-aced-7255944e5c59 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 7477881c-ec3b-49d6-aced-7255944e5c59, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.