Quant

Overview

TrojanDownloader:Win32/Quant (commonly known as **Quant Loader**) is a highly successful, commercially available malware downloader. Heavily advertised and sold on Russian-speaking underground hacking forums (like Exploit.in), Quant Loader acts as an Initial Access Broker (IAB) tool. Threat actors purchase Quant Loader to reliably bypass endpoint security and silently deliver their chosen secondary payloads (such as Locky ransomware, Pony stealers, or Formbook) to infected machines.

Understanding Quant Loader
To an end-user, a Quant Loader infection is completely invisible; it operates silently in the background. For a threat intelligence analyst, Quant Loader is a significant threat because of its commercial 'Malware-as-a-Service' (MaaS) nature. The developer constantly updates the loader with new anti-analysis and evasion techniques to ensure buyers get a high infection rate. The buyers use a provided web panel to configure which secondary payloads Quant should download based on the victim's geolocation and OS version.

Execution and Evasion Strategies
Buyers typically distribute Quant Loader via massive malspam campaigns (using weaponized Word macros) or through exploit kits like RIG (`T1189`). Upon execution, Quant employs complex anti-sandboxing checks (`T1497.001`)—delaying execution, checking for mouse movement, and verifying it isn't running in a known analyst VM (VirtualBox/VMWare). It copies itself to the `%AppData%` directory and establishes persistence via Registry Run keys (`T1547.001`). Quant Loader then reaches out to its C2 panel (often hosted on compromised sites) to fetch the secondary payload (`T1105`). It frequently uses process hollowing or API unhooking to inject and execute this secondary payload without alerting EDR solutions (`T1055`).

Indicators of Compromise & Impact
The impact depends entirely on what the buyer configured Quant to download (ranging from data theft to enterprise ransomware). Incident responders should investigate EDR alerts for suspicious child processes spawning from Office applications. Network telemetry will show initial HTTP check-ins to the Quant panel, followed by the downloading of secondary executable files. The presence of randomly named binaries in `%AppData%` with associated Run keys is a strong IoC.

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.
• T1566.001: Scan email attachments for malicious macros, scripts, or suspicious archive files.

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_QUANT_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Quant"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "quant" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Quant (Ransomware) Execution & Triage
id: 87338654-f916-5dd6-b442-1697cadb591e
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Quant malware family. Detects volume shadow copy deletion, boot status
  tampering, and recovery inhibition characteristic of modern ransomware operations.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/quant
- 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.ransomware
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1547_001
- attack.t1497_001
- attack.t1105
- attack.t1055
- attack.t1566_001
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \vssadmin.exe
    - \wmic.exe
    - \wbadmin.exe
    - \bcdedit.exe
    CommandLine|contains:
    - delete shadows
    - shadowcopy delete
    - resize shadowstorage
    - recoveryenabled no
    - ignoreallfailures
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: critical

rule MALWARE_WIN_QUANT_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Quant 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 = "quant" 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 endpoint immediately; if Quant Loader is detected, it has likely already downloaded and executed a high-severity secondary payload.
2. Use EDR to trace the execution chain: what process launched Quant, and what secondary processes did Quant subsequently spawn or inject into?
3. Review proxy logs for HTTP GET requests downloading `.exe` or `.dll` files immediately following the Quant infection timeline.
4. Capture a memory dump (RAM) to identify the injected secondary payload and extract the C2 configuration.

What to Avoid

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

1. Do not close the incident after removing the Quant executable; the primary threat is the secondary payload it delivered, which must also be identified and remediated.
2. Avoid assuming the threat actor is the developer of Quant; they are likely a customer who purchased it on a forum.

References & External Analysis

• Search "quant" on VirusTotal (External Analysis)
• Search "quant" on Any.Run (Sandbox Sandbox)
• Search "quant" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Ransomware)

Explore other documented threats in the same operational category:

• Genericrxaz
• Baiduwrapper
• Simple
• Gasti
• Enosch
• Adpernok
• Boaxxe
• Uwamson

Machine-readable

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