Jbonblanc

Overview

JBonBlanc (cataloged across security software as Trojan:Win32/JBonBlanc, Backdoor.Win32.JBonBlanc, and Trojan.JBonBlanc) is a legacy French-authored Delphi remote access backdoor trojan developed during the early-to-mid 2000s cybercrime era. Operating as an interactive remote administration implant, JBonBlanc opens custom TCP listening ports, connects to remote C2 controllers, and allows malicious operators to manipulate filesystem objects, log keystrokes, terminate security processes, and execute remote shell commands on infected Windows machines.

Known aliases

Threat reports may refer to this family under multiple names:

• Trojan:Win32/JBonBlanc
• Backdoor.Win32.JBonBlanc
• Trojan.JBonBlanc
• Win32/JBonBlanc.RAT
• Backdoor.JBonBlanc

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: French Delphi Rat Architectures

Known Derivatives & Downstream Variants: Jbonblanc V1.0 · Jbonblanc Pro · Win32/Jbonblanc.Gen

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:

• T1056.001: Implement Endpoint Detection and Response (EDR) to monitor for suspicious API calls related to keystroke interception. Enforce Multi-Factor Authentication (MFA) to render stolen passwords useless.
• T1059.003: Restrict execution of Windows Command Shell (cmd.exe) and block unauthorized batch scripts.
• T1071.001: Implement web filtering and SSL/TLS inspection to detect malicious command and control (C2) traffic hiding in HTTP/HTTPS.
• 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):

Exploited Vulnerabilities (CVEs)

This malware family is documented weaponizing the following common vulnerabilities and exposures:

• CVE-2010-2568 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).
• CVE-2012-0158 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).

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.

• 7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b
• 2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d

Delivery vectors

• Peer-to-peer file sharing networks disguised as software cracks and game cheat tools
• IRC DCC file transfer lures and malicious download links

Persistence mechanisms

• HKLM\Software\Microsoft\Windows\CurrentVersion\Run\JBonBlanc
• Startup folder shortcut in %APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup

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_JBONBLANC_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Jbonblanc"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "jbonblanc" ascii wide nocase
        $s2 = "trojan:win32/jbonblanc" ascii wide nocase
        $s3 = "backdoor.win32.jbonblanc" ascii wide nocase
        $s4 = "trojan.jbonblanc" ascii wide nocase
        $s5 = "win32/jbonblanc.rat" ascii wide nocase
        $s6 = "backdoor.jbonblanc" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Jbonblanc (Trojan) Execution & Triage
id: 2a5a17af-502b-53c0-a518-5024c1a7a320
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Jbonblanc 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/jbonblanc
- 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.t1056_001
- attack.t1059_003
- attack.t1071_001
- 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_JBONBLANC_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Jbonblanc 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 = "jbonblanc" 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 compromised endpoints to cut active remote command sessions.
2. Kill malicious JBonBlanc server processes running out of %TEMP% or %APPDATA% directories.
3. Delete persistence entries under HKLM and HKCU Software\Microsoft\Windows\CurrentVersion\Run.
4. Perform a complete system antimalware scan to eliminate secondary dropped tools.

What to Avoid

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

1. Do not execute software utilities downloaded from unverified peer-to-peer file-sharing networks.
2. Avoid bypassing operating system warnings when launching unsigned executable binaries.

References & External Analysis

• Kaspersky Threat Intelligence - Backdoor.Win32.JBonBlanc
• Trend Micro Threat Encyclopedia - Trojan.Win32.JBonBlanc
• NIST National Vulnerability Database - CVE-2010-2568
• Search "jbonblanc" on VirusTotal (External Analysis)
• Search "jbonblanc" on Any.Run (Sandbox Sandbox)
• Search "jbonblanc" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Qqshou
• Inexsmar
• Betabot
• Goldun
• Udpos
• A8P9Eklc
• Netsphere
• Filerepmalware

Machine-readable

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