Jacard

Overview

Jacard (cataloged in threat research and antivirus vendor databases under detections including Trojan:Win32/Jacard, Trojan.Jacard, and W32/Jacard) is a sophisticated Windows trojan and initial access stager active since 2013. Designed to compromise host endpoint integrity and establish covert surveillance, Jacard is distributed via malicious email attachments, compromised download portals, and pirated software cracks. Upon execution, Jacard unpacks in-memory, alters system settings to hide its background execution, and establishes persistence through Windows registry Run keys and scheduled tasks. Jacard hooks web browsers to intercept session traffic, collects host system configuration data and user credentials, and communicates with remote command-and-control (C2) servers over encrypted HTTP. Furthermore, it operates as a secondary downloader, retrieving and executing secondary malware modules including ransomware precursors, keyloggers, and cryptocurrency miners.

Known aliases

Threat reports may refer to this family under multiple names:

• Trojan:Win32/Jacard
• Trojan.Jacard
• W32/Jacard

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: Win32 Information Stealer Frameworks

Known Derivatives & Downstream Variants: Jacard.A · Jacard.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:

• 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.

• 1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d
• 2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e

Delivery vectors

• software_setup.exe
• jacard_patch.exe

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\JacardService
• %AppData%\Jacard\jacard.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_JACARD_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Jacard"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "jacard" ascii wide nocase
        $s2 = "trojan:win32/jacard" ascii wide nocase
        $s3 = "trojan.jacard" ascii wide nocase
        $s4 = "w32/jacard" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Jacard (Trojan) Execution & Triage
id: 21fab6e4-694b-53e1-8e4f-9bae920b4cce
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Jacard 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/jacard
- https://malware-families-catalog.systemhelpdesk.com/defensive/downloader-dropper-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.trojan
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1059_003
- attack.t1547_001
- attack.t1105
- attack.t1555_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_JACARD_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Jacard 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 = "jacard" 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 endpoint to halt the active exfiltration of browsing telemetry and the downloading of further adware modules.
2. Audit Windows Group Policies and the Registry to remove any forced extension installation policies (ExtensionInstallForcelist) created by the adware.
3. Deploy an enterprise adware removal tool (e.g., AdwCleaner) to locate and strip the deeply embedded registry hooks and watchdog services.
4. Force a complete reset of all installed web browsers to factory defaults to eradicate the rogue extensions and restore the homepage.

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; Jacard frequently uses GPOs and watchdog services to immediately reinstall itself.
2. Avoid ignoring the infection; adware tracking data is highly detailed and may expose corporate activities or access to internal portals.

References & External Analysis

• Microsoft Defender Security Intelligence - Trojan:Win32/Jacard
• Kaspersky Threat Intelligence - Trojan.Jacard Overview
• Search "jacard" on VirusTotal (External Analysis)
• Search "jacard" on Any.Run (Sandbox Sandbox)
• Search "jacard" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Addmepoint
• Skeeyah
• Wisbipuf
• Terabit_Virus_Maker
• Inexsmar
• Regrun
• Virtumonde
• Webdevaz

Machine-readable

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