Marketscore

Overview

Adware:Win32/Marketscore (also known historically as NetSetter) is a highly intrusive piece of adware/spyware that operates by fundamentally altering the victim's network configuration. Ostensibly marketed as 'market research' software that users 'agreed' to install in exchange for free software, Marketscore intercepts all web traffic to monitor browsing habits and inject targeted advertising, acting as a local Man-in-the-Middle (MitM) (`T1112`).

Understanding Marketscore (Historical Spyware)
To an end-user, Marketscore often caused significant network instability, slow browsing speeds, and a deluge of pop-up ads. For a security professional, it represents a severe privacy violation and a compromise of the network stack. Marketscore is infamous for its aggressive tactics and the difficulty of its removal, establishing the template for many modern, aggressive adware families.

Execution and Hijacking Mechanics
Marketscore was typically distributed via software bundles (e.g., attached to screensavers or early P2P clients). Upon installation, it required administrative privileges to deeply embed itself into the Windows networking stack. It commonly modified Winsock LSPs (Layered Service Providers) or installed a local proxy server, routing all HTTP/HTTPS traffic through its own engine (`T1112`). It modified the Windows Registry to ensure it started before the browser (`T1547.001`). Because it intercepted traffic at the network layer, it could monitor encrypted communications (by presenting its own SSL certificates) and inject ads into any page, regardless of the browser used.

Indicators of Compromise & Impact
The impact is the total loss of web browsing privacy and severe degradation of system performance. Host-based IoCs include the presence of Marketscore/NetSetter executables in `%ProgramFiles%`, the modification of `HKLM\System\CurrentControlSet\Services\WinSock2\Parameters\Protocol_Catalog9`, and the presence of unexpected local proxy settings in the Internet Options control panel. Network IoCs involve all web traffic being routed through unexpected local ports or directly to Marketscore's data collection servers.

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to the MITRE ATT&CK framework:

Generated Detections (Boilerplate)

These YARA and Sigma rules are auto-generated based on the family name and aliases. They must be heavily tuned before deployment in a production environment.

YARA Rule

rule MALWARE_WIN_MARKETSCORE {
    meta:
        description = "Detects Marketscore (advanced_threat)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "marketscore" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Marketscore Activity
id: 32bf146abd7c3336f5ff4c207c45348c
status: experimental
description: Detects generic indicators of the marketscore malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*marketscore*"
    condition: selection
level: medium

Containment & Response Steps

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

1. Use a specialized anti-malware tool; manual removal of Marketscore can break the Windows networking stack (Winsock) entirely.
2. If internet connectivity is broken after removal, use the `netsh winsock reset` command from an elevated command prompt to restore the default networking configuration.
3. Verify that all local proxy settings (`inetcpl.cpl` -> Connections -> LAN settings) have been cleared.
4. Reset all web browsers to their default configurations to ensure no malicious extensions or start pages remain.

What to Avoid

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

1. Do not simply delete the Marketscore executable files without properly unregistering the LSPs or proxies, as this will immediately kill the machine's internet connection.
2. Avoid accepting 'free' software offers that require you to join a 'research panel', as this is the primary vector for this type of spyware.

References & External Analysis

• Search "marketscore" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: advanced_threat)

Explore other malware families in the same category:

• Openshopper
• Pontoeb
• Prast
• Unigo
• Ayolog

Machine-readable

Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/marketscore.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.