PowerShell MsXml2.XmlHttp COM Object Instantiation

Alerts on PowerShell creating an MsXml2.XmlHttp COM object through New-Object -ComObject.

FreeReviewedSigma · Medium · v2

Product: windows
Category: ps_script
Author: frack113, MatilJ (SigmaHQ), DRL 1.1
Published: 2022-01-19
Updated: 2026-07-31

ATT&CK techniques

Execution

Recon
Resource Dev
Initial Access
Execution
- T1059.001PowerShell
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags PowerShell script content that creates a COM object using MsXml2.XmlHttp via New-Object -ComObject. Adversaries commonly use this pattern to programmatically make requests and execute subsequent logic within a PowerShell script. It relies on telemetry that captures PowerShell script block text, including Script Block Logging, to match the specific string combination in the script content.

Reporting behind it

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PowerShell MsXml2.XmlHttp COM Object Instantiation

Pivot detection · T1059.001 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

powershell-msxml2-xmlhttp-via-com-object-creation-78aa1347

title: PowerShell MsXml2.XmlHttp COM Object Instantiation
id: b55e56e4-fd36-461c-beb2-d1bb210852a0
status: test
description: This rule flags PowerShell script content that creates a COM object using MsXml2.XmlHttp via New-Object -ComObject. Adversaries commonly use this pattern to programmatically make requests and execute subsequent logic within a PowerShell script. It relies on telemetry that captures PowerShell script block text, including Script Block Logging, to match the specific string combination in the script content.
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1059.001/T1059.001.md#atomic-test-7---powershell-msxml-com-object---with-prompt
  - https://learn.microsoft.com/en-us/previous-versions/windows/desktop/ms766431(v=vs.85)
  - https://www.trendmicro.com/en_id/research/22/e/uncovering-a-kingminer-botnet-attack-using-trend-micro-managed-x.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/powershell/powershell_script/posh_ps_msxml_com.yml
author: frack113, MatilJ, Huntrule Team
date: 2022-01-19
modified: 2022-05-19
tags:
  - attack.execution
  - attack.t1059.001
logsource:
  product: windows
  category: ps_script
  definition: "Requirements: Script Block Logging must be enabled"
detection:
  selection:
    ScriptBlockText|contains|all:
      - New-Object
      - -ComObject
      - MsXml2.
      - XmlHttp
  condition: selection
falsepositives:
  - Legitimate administrative script
level: medium
license: DRL-1.1
related:
  - id: 78aa1347-1517-4454-9982-b338d6df8343
    type: derived

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