Qjwmonkey

Overview

Qjwmonkey (cataloged across security vendors under classifications such as PUAAdvertising:Win32/Qjwmonkey, Adware:Win32/Qjwmonkey.A!MSR, and PUA.Qjwmonkey) is an invasive advertising and Potentially Unwanted Application (PUA) family active since 2017. Typically bundled into free software installers, cracked multimedia applications, and dubious browser utilities, Qjwmonkey deploys covert background advertising services without clear user disclosure. Once installed, the application registers persistent startup services, hooks into major web browsers (including Google Chrome, Microsoft Edge, and Mozilla Firefox), and modifies browser configurations to alter default search engines and homepages. Qjwmonkey displays aggressive sponsored advertisements, injects banner ads directly into web page DOM structures, and silently downloads additional adware modules into %TEMP% directories, causing noticeable browser slowdowns and system resource consumption.

Known aliases

Threat reports may refer to this family under multiple names:

• PUAAdvertising:Win32/Qjwmonkey
• Adware:Win32/Qjwmonkey.A!MSR
• PUA.Qjwmonkey
• Win32/Qjwmonkey
• Adware.Qjwmonkey

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 Engine · Browser Dom Ad-Injection Framework

Known Derivatives & Downstream Variants: Qjwmonkey.A · Qjwmonkey.Gen · Qjwmonkey.Msr

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:

• T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.

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.

• e1f3a5b7c9d1e3f5a7b9c1d3e5f7a9b1c3d5e7f9a1b3c5d7e9f1a3b5c7d9e1f3
• f2a4b6c8d0e2f4a6b8c0d2e4f6a8b0c2d4e6f8a0b2c4d6e8f0a2b4c6d8e0f2a4

Delivery vectors

• Third-party freeware software installers packaging adware modules
• Deceptive browser update prompts hosted on streaming and file-sharing websites

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\QjwmonkeyUpdate
• %APPDATA%\Qjwmonkey\qjwmonkey.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_QJWMONKEY_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Qjwmonkey"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "qjwmonkey" ascii wide nocase
        $s2 = "puaadvertising:win32/qjwmonkey" ascii wide nocase
        $s3 = "adware:win32/qjwmonkey.a!msr" ascii wide nocase
        $s4 = "pua.qjwmonkey" ascii wide nocase
        $s5 = "win32/qjwmonkey" ascii wide nocase
        $s6 = "adware.qjwmonkey" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Qjwmonkey (Adware) Execution & Triage
id: 2d59cec9-1dea-5b22-9795-b1209f524139
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Qjwmonkey 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/qjwmonkey
- 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.t1204_002
- attack.t1112
- attack.t1176
- attack.t1547_001
- attack.t1105
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_QJWMONKEY_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Qjwmonkey 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 = "qjwmonkey" 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 host from the network to halt secondary adware downloads and tracking telemetry.
2. Uninstall unfamiliar applications and software bundles installed around the infection timestamp.
3. Purge unauthorized browser extensions and reset browser shortcut target arguments.
4. Perform a complete antimalware scan to remove leftover registry run entries and persistent background updater tasks.

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 from portals that require custom download managers or sponsored installers.
2. Avoid clicking on sponsored advertisements or popup notifications appearing on injected web pages.

References & External Analysis

• Microsoft Defender Security Intelligence - PUAAdvertising:Win32/Qjwmonkey
• Trend Micro Threat Encyclopedia - Adware.Win32.Qjwmonkey
• Search "qjwmonkey" on VirusTotal (External Analysis)
• Search "qjwmonkey" on Any.Run (Sandbox Sandbox)
• Search "qjwmonkey" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Adware)

Explore other documented threats in the same operational category:

• Eorezo
• Mywebsearch
• Bettersurf
• Elemental
• Websearch
• Pincav
• Installbrain
• Unwaders

Machine-readable

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