Dlguide

Overview

DownloadGuide (detected across commercial threat intelligence as PUA:Win32/DownloadGuide, Adware:Win32/DownloadGuide, and Win32/DownloadGuide.Bundler) is a deceptive software installer wrapper and download manager analyzed by Microsoft Defender and Malwarebytes. DownloadGuide operates primarily as an affiliate-driven monetization installer deployed across third-party freeware mirrors, torrent platforms, and file-hosting portals. When users download open-source applications, video codecs, or gaming utilities, the primary download link serves the DownloadGuide executable wrapper rather than the clean software binary. Upon launch, the wrapper displays an interface utilizing dark UX patterns—including obscured decline buttons, pre-checked opt-in boxes, and misleading license agreements—to gain user authorization for deploying secondary payloads. In the background, DownloadGuide contacts affiliate command-and-control servers via HTTP/HTTPS to retrieve lists of promotional packages, which are staged in %Temp% and executed silently. These secondary payloads include persistent adware engines, search engine redirectors, rogue registry optimizers, and tracking toolbars. To maintain persistence, DownloadGuide configures Windows Scheduled Tasks and auto-start registry values under HKCU\Software\Microsoft\Windows\CurrentVersion\Run.

Known aliases

Threat reports may refer to this family under multiple names:

• PUA:Win32/DownloadGuide
• Adware:Win32/DownloadGuide
• Win32/DownloadGuide.Bundler
• PUP.Optional.DownloadGuide
• Adware.DownloadGuide

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: Generic_Ppi_Wrapper_Engine

Known Derivatives & Downstream Variants: Downloadguide.B · Win32.Pua.Downloadguide

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.

• a1f8e43d96c82701b2a95c478e12d3049b5c8712e34f601a9c8b7e6d5a4f3b2c
• b2c9d0e1f3a4567890123456789abcdef0123456789abcdef0123456789abcde

Delivery vectors

• Freeware download aggregator portals and deceptive download buttons mimicking official open-source project mirrors
• Affiliate marketing redirects leading to packaged wrapper executables

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\DownloadGuideUpdate
• Scheduled Task created via schtasks /create /tn 'DownloadGuideService' /tr '%AppData%\DownloadGuide\dgservice.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_DLGUIDE_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Dlguide"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "dlguide" ascii wide nocase
        $s2 = "pua:win32/downloadguide" ascii wide nocase
        $s3 = "adware:win32/downloadguide" ascii wide nocase
        $s4 = "win32/downloadguide.bundler" ascii wide nocase
        $s5 = "pup.optional.downloadguide" ascii wide nocase
        $s6 = "adware.downloadguide" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Dlguide (Pua) Execution & Triage
id: 6d661b52-b508-5a31-b005-343e00d8d862
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Dlguide 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/dlguide
- 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.t1105
- attack.t1204_002
- attack.t1053_005
- attack.t1547_001
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_DLGUIDE_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Dlguide 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 = "dlguide" 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. Isolate the affected endpoint to prevent secondary payload staging and affiliate C2 beaconing.
2. Inspect and remove rogue scheduled tasks named 'DownloadGuideUpdate' or similar installer task entries.
3. Purge the local user %Temp% directory to eliminate cached installer wrappers and downloaded MSI/EXE binaries.
4. Execute a comprehensive antimalware sweep using Microsoft Defender or Malwarebytes to detect dropped browser hijackers.

What to Avoid

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

1. Do not permit standard users to download installation media from non-vetted third-party software directories.
2. Do not execute software wrappers with administrative elevation when prompted during freeware setup.

References & External Analysis

• Microsoft Defender Security Intelligence - PUA:Win32/DownloadGuide Threat Profile
• Malwarebytes Labs Threat Encyclopedia - Adware.DownloadGuide Detection
• NIST National Vulnerability Database - CVE-2015-1641 Details
• Search "dlguide" on VirusTotal (External Analysis)
• Search "dlguide" on Any.Run (Sandbox Sandbox)
• Search "dlguide" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Pua)

Explore other documented threats in the same operational category:

• Runbooster
• Dnscleaner
• Prepscram
• Systweak
• Cloudguard
• Onesystemcare
• Icloader
• Optimizer

Machine-readable

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