Bundlore

Overview

Bundlore (tracked across security vendors under designations including Adware:OSX/Bundlore, Adware:Win32/Bundlore, OSX.Bundlore, and Shlayer/Bundlore variant) is a cross-platform adware bundler and unwanted application distribution platform affecting both macOS and Microsoft Windows operating systems. Known for its sophisticated evasive packaging, Bundlore typically masquerades as illegitimate media players, Flash Player updates, video converters, or software cracks hosted on malicious landing pages. Upon execution, Bundlore runs anti-analysis routines to detect virtual machines, debugging environments, and security monitoring software. The installer dynamically contacts remote advertising C2 servers to fetch encrypted configuration payloads. Bundlore extracts and installs multiple unwanted components, including rogue browser extensions, proxy configurations, and man-in-the-middle certificates. These components inject banners, pop-up ads, and affiliate tracking cookies into encrypted HTTPS web traffic, while establishing persistent autostart mechanisms (such as macOS LaunchAgents/LaunchDaemons or Windows Scheduled Tasks and Run registry entries).

Known aliases

Threat reports may refer to this family under multiple names:

• Adware:OSX/Bundlore
• Adware:Win32/Bundlore
• OSX/Bundlore
• Win32/Bundlore
• Bundlore Installer
• OSX.Bundlore

MITRE ATT&CK Techniques

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

MITRE D3FEND™ Defensive Countermeasures

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

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_BUNDLORE_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Bundlore"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "bundlore" ascii wide nocase
        $s2 = "adware:osx/bundlore" ascii wide nocase
        $s3 = "adware:win32/bundlore" ascii wide nocase
        $s4 = "osx/bundlore" ascii wide nocase
        $s5 = "win32/bundlore" ascii wide nocase
        $s6 = "bundlore installer" ascii wide nocase
        $s7 = "osx.bundlore" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Bundlore (Adware) Execution & Triage
id: d73ff348-9cfb-5df4-ae7b-d6dcd142d55e
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Bundlore 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/bundlore
- 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.t1176
- attack.t1543_001
- attack.t1543_004
- attack.t1547_001
- attack.t1053_005
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_BUNDLORE_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Bundlore 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 = "bundlore" 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. Use enterprise endpoint management tools to forcefully remove the rogue browser extensions and reset the default search providers.
2. Audit the properties of all browser shortcuts (`.lnk` files) on the user's Desktop, Taskbar, and Start Menu to remove any appended malicious URLs.
3. Use the Windows Control Panel to uninstall the bundled applications, followed by deploying an adware removal tool (e.g., AdwCleaner) to strip the remaining Scheduled Tasks and registry hooks.
4. Force a complete reset of all installed web browsers to factory defaults.

What to Avoid

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

1. Do not rely solely on the browser's 'remove extension' button; Bundlore uses watchdog services (Scheduled Tasks) to immediately re-apply the malicious settings.
2. Avoid ignoring the infection; the affiliate networks powering these hijackers often serve malicious advertisements (malvertising) that can lead to severe malware infections.

References & External Analysis

• Microsoft Defender Threat Encyclopedia - Adware:Win32/Bundlore
• Sophos Threat Center - OSX/Bundlore Technical Analysis
• MITRE ATT&CK - Subvert Trust Controls: Install Root Certificate (T1553.004)
• Search "bundlore" on VirusTotal (External Analysis)
• Search "bundlore" on Any.Run (Sandbox Sandbox)
• Search "bundlore" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Adware)

Explore other documented threats in the same operational category:

• Tuscas
• Elex
• Fusioncore
• Kuaiba
• Downloadhelper
• Inbox
• Unwaders
• Youxun

Machine-readable

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