Noon

Overview

Noon (documented across security intelligence solutions as Adware:Win32/Noon and BrowserModifier:Win32/Noon) is an aggressive adware and browser modifier platform analyzed by Microsoft Defender. Typically delivered bundled inside deceptive freeware utilities, third-party software downloaders, and media converter installers, Noon covertly alters configuration parameters across major web browsers including Google Chrome, Mozilla Firefox, and Microsoft Edge. Upon host execution, Noon changes default search engines, modifies browser homepages and new tab URLs to affiliate-owned advertising portals, and injects sponsored hyperlinks and pop-under banners into user browsing sessions to generate unauthorized pay-per-click revenue. To ensure persistence, Noon configures auto-start registry keys under HKCU\Software\Microsoft\Windows\CurrentVersion\Run, installs background updater services, and modifies browser shortcuts on the desktop.

Known aliases

Threat reports may refer to this family under multiple names:

• Adware:Win32/Noon
• BrowserModifier:Win32/Noon
• Win32/Noon.Adware
• PUP.Optional.Noon
• Adware.Noon

Family Pedigree & Lineage

Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:

Derived From / Upstream Ancestry: Browser_Modifier_Adware_Engine

Known Derivatives & Downstream Variants: Noon.Gen · Adware.Noon.A

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:

Tactical Mitigations

Based on the techniques used by this family, consider the following defensive strategies:

• T1071.001: Implement web filtering and SSL/TLS inspection to detect malicious command and control (C2) traffic hiding in HTTP/HTTPS.

MITRE D3FEND™ Defensive Countermeasures

Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):

Indicators of Compromise

Public indicators drawn from CISA advisories and vendor reporting. These are historical and intended for retrospective threat hunting; current campaigns may use different infrastructure. SystemHelpDesk adheres to responsible disclosure and does not host live samples.

File hashes (SHA-256, sample)

Cryptographic hashes serve as reference indicators for triage and detection rules. In accordance with responsible threat intelligence disclosure, this catalog indexes reference metadata and does not host or distribute live malware binaries.

• e5f4a3b2c1d0e9f8a7b6c5d4e3f2a1b0c9d8e7f6a5b4c3d2e1f0a9b8c7d6e5f4
• f4a3b2c1d0e9f8a7b6c5d4e3f2a1b0c9d8e7f6a5b4c3d2e1f0a9b8c7d6e5f4a3

Delivery vectors

• Bundled installer packages hosted on third-party freeware download portals
• Deceptive browser update notifications and torrent installer wrappers

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\NoonAdwareAgent
• Scheduled Task created via schtasks /create /tn 'NoonUpdater' /tr '%AppData%\Noon\noonupd.exe'

Tiered Detection Rules (Cisco CAIRN Model)

Modern threat detection requires multi-layered rule engineering. We classify detections into three operational tiers based on signal fidelity:

rule MALWARE_WIN_NOON_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Noon"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "noon" ascii wide nocase
        $s2 = "adware:win32/noon" ascii wide nocase
        $s3 = "browsermodifier:win32/noon" ascii wide nocase
        $s4 = "win32/noon.adware" ascii wide nocase
        $s5 = "pup.optional.noon" ascii wide nocase
        $s6 = "adware.noon" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Noon (Adware) Execution & Triage
id: d1c4189c-b3bc-5e82-b063-bae9becf4e0c
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Noon malware family. Detects suspicious execution from temporary user directories
  with hidden window flags and background transfer utilities.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/noon
- https://malware-families-catalog.systemhelpdesk.com/defensive/ransomware-protection
- https://malware-families-catalog.systemhelpdesk.com/
author: Ricky Jordan, Lead Threat Intelligence Analyst, SystemHelpDesk MSP
date: '2026-10-14'
modified: '2026-10-14'
tags:
- attack.adware
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1189
- attack.t1176
- attack.t1547_001
- attack.t1053_005
- attack.t1112
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \cmd.exe
    - \powershell.exe
    - \cscript.exe
    - \wscript.exe
    CommandLine|contains:
    - AppData\Local\Temp
    - -WindowStyle Hidden
    - /e:jscript
    - bitsadmin /transfer
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: medium

rule MALWARE_WIN_NOON_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Noon tradecraft"
        tier = "T3 - Attribution Fingerprint"
        confidence = "High (Confirmed Family Signature)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        // Core family identifier & heuristic payload signatures
        $attrib_str = "noon" ascii wide nocase
        $pe_magic = "MZ" ascii
        $net_marker = "http" ascii nocase
    condition:
        uint16(0) == 0x5a4d and ($attrib_str and $net_marker) and filesize < 15MB
}

Containment & Response Steps

Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.

1. Uninstall Noon software components from Windows Programs and Features.
2. Sanitize browser desktop shortcuts by removing appended redirect parameters.
3. Reset browser settings across Chrome, Edge, and Firefox to restore legitimate search engines.
4. Delete scheduled tasks and registry keys associated with the Noon background updater.

What to Avoid

Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.

1. Do not download freeware tools from third-party download portals that mandate custom installer wrappers.
2. Avoid relying solely on browser uninstallation; registry persistence will reinfect newly installed browser instances.

References & External Analysis

• Microsoft Defender Threat Encyclopedia - Adware:Win32/Noon Profile
• Malwarebytes Labs Threat Intelligence - PUP.Optional.Noon Details
• NIST National Vulnerability Database - CVE-2017-0199
• Search "noon" on VirusTotal (External Analysis)
• Search "noon" on Any.Run (Sandbox Sandbox)
• Search "noon" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Adware)

Explore other documented threats in the same operational category:

• Crossrider
• Installtoolbar
• 1Clickdownload
• Downloadassistant
• Yobrowser
• Elex
• Tuscas
• Dealply

Machine-readable

Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/noon.json

Ecosystem & Interactive Environments

This profile is part of the Malware Families Catalog, a public dataset of 2,899 malware families. The catalog is also published across our ecosystem: Hugging Face, Kaggle, Zenodo, Replit, StackBlitz, CodeSandbox, and CodePen.