Chthonic

Overview

Trojan:Win32/Chthonic is an advanced, highly modular banking trojan and direct evolutionary offshoot of the Zeus (Zbot) codebase discovered by Kaspersky Lab researchers in late 2014. Chthonic represents a hybrid crimeware architecture integrating components from Andromeda and SmokeLoader to deploy encrypted virtual file systems and polymorphic shellcode loaders. The malware specifically targeted over 150 major banking institutions and 20 payment processing gateways across 15 nations, including the United States, United Kingdom, Russia, Japan, Spain, and Italy. Chthonic executes via process hollowing into explorer.exe, msiexec.exe, and svchost.exe, injecting malicious code hooks into Internet Explorer, Mozilla Firefox, and Google Chrome web sessions. Its modular framework features clandestine Virtual Network Computing (hidden VNC) for real-time operator control, remote audio and video capture from connected microphones and webcams, and automated webinjects that manipulate banking DOM elements to bypass two-factor authentication (2FA). Chthonic communications employ AES-256 encrypted C2 channels with dynamic domain generation fallback routines, establishing persistent scheduled tasks and registry Run key autoruns to evade forensic detection.

Known aliases

Threat reports may refer to this family under multiple names:

• Chthonic
• Trojan.Chthonic
• Win32/Chthonic
• Zeus Chthonic
• Zbot.Chthonic

Threat Actor Attribution

Attribution is probabilistic, not a science. Each link below states its confidence level and the evidence behind it.

• Russian-speaking Cybercrime Underground High confidence
  Basis:
• Zeus Derivative Developers High confidence
  Basis:

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: Zeus · Andromeda

Known Derivatives & Downstream Variants: Chthonic V1.0 · Chthonic Vnc Module · Chthonic Webinject Edition

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.
• T1071.001: Implement web filtering and SSL/TLS inspection to detect malicious command and control (C2) traffic hiding in HTTP/HTTPS.
• T1113: Monitor for frequent or unauthorized screen captures or clipboard reads. Restrict background applications from accessing desktop APIs.
• T1185: Enforce strong MFA and use browser isolation or hardened browsers for sensitive financial or administrative portals to defeat session hijacking.
• 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):

Exploited Vulnerabilities (CVEs)

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

• CVE-2014-1761 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).
• CVE-2014-4114 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).

Command & Control (C2) and Network Profile

How this family talks to its operators. C2 traffic can often identify a family even when its code and configuration are hard to analyse. Ports and patterns are historical and change between campaigns, so use them as hunting leads rather than block-only rules.

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.

• 4b6c33fef79ebbcce763ffca07fa81215b493c4e3658ebc76b9ee2f8719cb49d
• 89a27eb2762eb295fe3509bc9f636257a3e7ef7b1bcfd1a7b489d81d6f228b7e

Delivery vectors

• malicious_rtf_exploit
• rig_exploit_kit

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run
• Scheduled Tasks

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_CHTHONIC_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Chthonic"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "chthonic" ascii wide nocase
        $s2 = "chthonic" ascii wide nocase
        $s3 = "trojan.chthonic" ascii wide nocase
        $s4 = "win32/chthonic" ascii wide nocase
        $s5 = "zeus chthonic" ascii wide nocase
        $s6 = "zbot.chthonic" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Chthonic (Banking Trojan) Execution & Triage
id: 137ac124-c599-57e8-aefa-d8708f8aeaf8
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Chthonic malware family. Detects recon staging, certutil file payload staging,
  and web-inject process proxying characteristic of banking trojan initial loaders.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/chthonic
- https://malware-families-catalog.systemhelpdesk.com/defensive/banking-trojan-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.banking-trojan
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1055_012
- attack.t1185
- attack.t1056_001
- attack.t1071_001
- attack.t1113
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \svchost.exe
    - \explorer.exe
    - \msiexec.exe
    - \certutil.exe
    CommandLine|contains:
    - -urlcache
    - -split -f
    - ipconfig /all
    - route print
    - netstat -ano
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: high

rule MALWARE_WIN_CHTHONIC_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Chthonic 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 = "chthonic" 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. Terminate injected browser processes and isolate endpoint from internal network segments.
2. Revoke compromised online banking credentials and enforce mandatory out-of-band transaction approvals.
3. Block inbound network connections matching documented Chthonic C2 IP addresses and dynamic DNS domains.
4. Apply security patches for Microsoft Office vulnerabilities CVE-2014-1761 and CVE-2014-4114.

What to Avoid

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

1. Do not enter secondary one-time passwords into browser popups requesting verification during active banking sessions.
2. Do not execute unverified macros or RTF email attachments received from external senders.
3. Avoid relying solely on SMS-based 2FA which can be circumvented via browser webinject manipulation.

References & External Analysis

• Kaspersky Securelist Analysis: Chthonic A New Zeus Clone
• Trend Micro Security Intelligence: Chthonic Banking Trojan
• NIST National Vulnerability Database CVE-2014-1761
• Search "chthonic" on VirusTotal (External Analysis)
• Search "chthonic" on Any.Run (Sandbox Sandbox)
• Search "chthonic" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Banking Trojan)

Explore other documented threats in the same operational category:

• Zeusvm
• Goznym
• Spyeye
• A_311_Death
• Carberp
• Guildma
• Ursnif
• Bancos

Machine-readable

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