Installcore

Overview

PUA:Win32/InstallCore (widely cataloged across endpoint telemetry as ADW_INSTALLCORE, PUP.Optional.InstallCore, or PUA.Win32.InstallCore) is an aggressive software installer wrapper and monetization platform operated by ironSource. Widely integrated into third-party software download portals, repackaged freeware utilities, and torrent distributors, InstallCore wraps legitimate application binaries inside an evasive multi-step installer wizard. During setup, it employs deceptive user interface patterns (dark patterns) with pre-checked consent boxes and confusing opt-out buttons to covertly bundle unwanted software—including browser hijackers, persistent adware daemons, fake system optimizers, and tracking toolbars. InstallCore alters default browser homepage configurations, replaces default search providers with ad-supported syndicates, injects background services, and frequently drops auxiliary adware payloads directly onto Windows endpoints.

Known aliases

Threat reports may refer to this family under multiple names:

• InstallCore
• PUA:Win32/InstallCore
• ADW_INSTALLCORE
• PUP.Optional.InstallCore
• PUA.Win32.InstallCore
• InstallCore Bundler
• Adware.InstallCore

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 Adware Wrapper & Download Manager Lineage

Known Derivatives & Downstream Variants: Pua:Win32/Installcore.A · Adw_Installcore.Gen · Pua.Win32.Installcore.B

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:

• T1059.003: Restrict execution of Windows Command Shell (cmd.exe) and block unauthorized batch scripts.

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.

• b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0123456789abcdef0123456789abcdef
• 0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef

Delivery vectors

• Third-party freeware download hosting portals
• Repackaged open-source software installers
• Search engine ad redirection links

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\InstallCoreUpdate
• Browser extension manifests installed in AppData directories

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_INSTALLCORE_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Installcore"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "installcore" ascii wide nocase
        $s2 = "installcore" ascii wide nocase
        $s3 = "pua:win32/installcore" ascii wide nocase
        $s4 = "adw_installcore" ascii wide nocase
        $s5 = "pup.optional.installcore" ascii wide nocase
        $s6 = "pua.win32.installcore" ascii wide nocase
        $s7 = "installcore bundler" ascii wide nocase
        $s8 = "adware.installcore" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Installcore (Pua) Execution & Triage
id: fc779292-8134-58e8-9ce4-a55a9f3bc072
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Installcore 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/installcore
- 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.pua
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1189
- attack.t1547_001
- attack.t1176
- attack.t1059_003
- attack.t1082
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_INSTALLCORE_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Installcore 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 = "installcore" 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. Quarantine the Installcore installer package and terminate any active background browser helper processes or pop-up launchers.
2. Audit all web browser extensions, proxy configurations, and shortcut targets (.lnk files) on desktop and taskbar to purge malicious command-line parameters appended by Installcore.
3. Purge unauthorized Scheduled Tasks and Registry Run entries configured by Installcore to re-spawn bundled greyware packages.
4. Perform a comprehensive secondary anti-malware scan to ensure no hidden trojan downloaders or cryptominers were dropped alongside Installcore.

What to Avoid

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

1. Do not dismiss Installcore as harmless nuisance software; greyware distribution networks frequently pivot to delivering high-severity malware payloads.
2. Avoid clicking interactive prompts or fake 'update' dialogs generated by Installcore, which often trigger secondary drive-by downloads.

References & External Analysis

• Microsoft Defender Threat Encyclopedia - PUA:Win32/InstallCore
• Trend Micro Threat Encyclopedia - ADW_INSTALLCORE
• Sophos Threat Center - InstallCore PUA Analysis
• Search "installcore" on VirusTotal (External Analysis)
• Search "installcore" on Any.Run (Sandbox Sandbox)
• Search "installcore" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Pua)

Explore other documented threats in the same operational category:

• Installmonster
• Appset
• Gt32Supportgeeks
• Playtech
• Soft32Dl
• Systweak
• Icloader
• Pupstudio

Machine-readable

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