Spigot

Overview

Spigot (documented by Microsoft Defender, Malwarebytes, and Sophos as BrowserModifier:Win32/Spigot, Adware:Win32/Spigot, and PUP.Optional.Spigot) is a widely distributed commercial adware and browser modifier platform developed by Spigot, Inc. Bundled with hundreds of freeware utilities, PDF converters, and media utilities, Spigot deploys unwanted browser extensions (such as CouponDropDown, Search Assistant, and Application Mover) across Google Chrome, Firefox, and Internet Explorer. Once embedded in browser environments, Spigot intercepts DNS queries and HTTP search requests, redirecting users to sponsored partner search portals and injecting unsolicited coupon overlays, pop-unders, and inline advertising links into visited web pages. Spigot maintains host persistence via HKCU Run registry entries, Windows Scheduled Tasks, and background auto-updating binaries installed under %AppData% and %ProgramFiles%.

Known aliases

Threat reports may refer to this family under multiple names:

• BrowserModifier:Win32/Spigot
• Adware:Win32/Spigot
• Win32/Spigot
• PUP.Optional.Spigot
• Adware.Spigot
• Spigot.CouponDropDown

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: Commercial_Browser_Monetization_Platform

Known Derivatives & Downstream Variants: Spigot_Coupondropdown · Spigot_Search_Assistant

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.

• d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6
• e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7

Delivery vectors

• Software bundlers packaged with freeware PDF converters and audio utilities
• Deceptive sponsored software download portals

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\SpigotUpdate
• Scheduled Task created via schtasks /create /tn 'SpigotAppUpdate' /tr '%AppData%\Spigot\updater.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_SPIGOT_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Spigot"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "spigot" ascii wide nocase
        $s2 = "browsermodifier:win32/spigot" ascii wide nocase
        $s3 = "adware:win32/spigot" ascii wide nocase
        $s4 = "win32/spigot" ascii wide nocase
        $s5 = "pup.optional.spigot" ascii wide nocase
        $s6 = "adware.spigot" ascii wide nocase
        $s7 = "spigot.coupondropdown" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Spigot (Adware) Execution & Triage
id: 4f7304a2-9a70-5f57-9ef2-117496c6e82e
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Spigot 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/spigot
- 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_SPIGOT_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Spigot 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 = "spigot" 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 Spigot utilities (e.g., CouponDropDown, Search Assistant) via Windows Programs and Features.
2. Remove unauthorized extensions from all web browsers and reset default search providers to enterprise standards.
3. Delete Spigot registry auto-start entries under HKCU\Software\Microsoft\Windows\CurrentVersion\Run.
4. Purge Spigot updater tasks from Windows Task Scheduler and run an enterprise endpoint antimalware scan.

What to Avoid

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

1. Do not allow users to install unauthorized browser toolbars or price-comparison add-ons.
2. Avoid relying solely on basic browser extension removal without cleaning system updater binaries, which will reinstall extensions.

References & External Analysis

• Microsoft Defender Security Intelligence - BrowserModifier:Win32/Spigot Details
• Malwarebytes Labs Threat Intelligence - PUP.Optional.Spigot Profile
• Sophos Threat Intelligence - Adware.Spigot Analysis
• Search "spigot" on VirusTotal (External Analysis)
• Search "spigot" on Any.Run (Sandbox Sandbox)
• Search "spigot" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Adware)

Explore other documented threats in the same operational category:

• Appscience
• Aero
• Mailru
• Multiplug
• Yobrowser
• Dlsponsor
• Gorillaprice
• Browserio

Machine-readable

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