A_311_Death

Overview

A-311 Death is a seminal Remote Administration Tool (RAT) and Trojan active during the early-to-mid 2000s threat landscape. Operating primarily as an invasive stealth backdoor, it afforded remote operators unconstrained interactive control over compromised Windows endpoints. Architecturally, A-311 Death evolved from basic client-server administrative sockets into an advanced credential-harvesting weapon, introducing form-grabbing routines targeting web browser sessions, Transaction Authentication Number (TAN) interception for banking fraud, and inline HTTP redirection mechanisms designed for banking phishing attacks. Multiple threat researchers correlate A-311 Death directly with the emergence of the notorious Haxdoor malware family, frequently identifying it as the foundational toolkit and builder from which Haxdoor variants branched. The trojan exhibited custom rootkit cloaking features to mask its process image and disk artifacts, and famously issued the greeting string 'A-311 Death welcome' across established C2 sessions upon client authentication. Distributed commercially across underground forums in Standard, Full, and Ultimate tiers, A-311 Death stood as one of the earliest commercial precursors to modern Malware-as-a-Service (MaaS) crime kits.

Known aliases

Threat reports may refer to this family under multiple names:

• Haxdoor
• A-311
• Trojan.Haxdoor.A311

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: Haxdoor_Banking_Rootkit

Known Derivatives & Downstream Variants: Haxdoor.A311 · A-311_Death_Trojan · Goldun

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: Restrict execution of scripting languages such as PowerShell, VBScript, or Python to authorized administrators. Enforce Script Block Logging.

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.

• 2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f
• 3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a

Delivery vectors

• Spear-phishing emails delivering weaponized Microsoft Office documents exploiting CVE-2006-0003
• Drive-by download landing pages utilizing Internet Explorer memory corruption exploits (CVE-2006-1359)

Persistence mechanisms

• System service registration installing kernel-mode rootkit drivers in %SystemRoot%\System32\drivers
• HKLM\Software\Microsoft\Windows NT\CurrentVersion\Windows\AppInit_DLLs

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_A_311_DEATH_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for A_311_Death"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "a_311_death" ascii wide nocase
        $s2 = "haxdoor" ascii wide nocase
        $s3 = "a-311" ascii wide nocase
        $s4 = "trojan.haxdoor.a311" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - A_311_death (Banking Trojan) Execution & Triage
id: 8cffd518-0c8e-5ca3-bbca-b5796f3d04a4
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the A_311_death 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/a_311_death
- 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.t1059
- attack.t1055
- attack.t1056_001
- attack.t1112
- attack.t1569
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_A_311_DEATH_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for A_311_Death 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 = "a_311_death" 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 hosts from network segments to sever active command sockets and prevent exfiltration.
2. Terminate spawned backdoor binaries and inspect hook DLLs injected into explorer.exe or browser processes.
3. Scrub malicious registry autorun entries in HKLM\Software\Microsoft\Windows\CurrentVersion\Run and system service registrations.
4. Reset all financial, administrative, and domain credentials accessed from the impacted workstation.

What to Avoid

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

1. Do not execute system recovery without memory triage, as rootkit components will evade basic file-system scanning.
2. Do not access production banking or administrative portals until full operating system re-imaging is confirmed.

References & External Analysis

• Malware Museum
• Securelist
• Search "a_311_death" on VirusTotal (External Analysis)
• Search "a_311_death" on Any.Run (Sandbox Sandbox)
• Search "a_311_death" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Banking Trojan)

Explore other documented threats in the same operational category:

• Danabot
• Ursnif
• Gozi
• Dreambot
• Bancos
• Guildma
• Trickster
• Alien

Machine-readable

Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/a_311_death.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.