Schoolbus

Overview

Schoolbus (cataloged across security software as Backdoor:Win32/Schoolbus, Trojan.Win32.Schoolbus, and Backdoor.Schoolbus) is a classic early 2000s Remote Access Trojan created in Microsoft Visual Basic. Developed during the retro Windows backdoor era, Schoolbus operated a dedicated client-server architecture over custom TCP port 2001 (and configurable high-range ports), providing remote attackers with full interactive control over infected workstations. Capabilities included keystroke logging, desktop screen capture, interactive remote shell execution, system rebooting, and unauthorized file system browsing. Schoolbus was commonly distributed through peer-to-peer file sharing networks, IRC chat transfers, and trojanized gaming cracks.

Known aliases

Threat reports may refer to this family under multiple names:

• Backdoor:Win32/Schoolbus
• Trojan.Win32.Schoolbus
• Backdoor.Schoolbus
• Win32/Schoolbus.RAT
• Schoolbus.Server

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: Visual Basic Rat Frameworks

Known Derivatives & Downstream Variants: Schoolbus V1.0 · Schoolbus V1.2 · Schoolbus Pro

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.

• c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4
• 9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f

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\SchoolbusServer
• Startup folder shortcut placed under %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_SCHOOLBUS_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Schoolbus"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "schoolbus" ascii wide nocase
        $s2 = "backdoor:win32/schoolbus" ascii wide nocase
        $s3 = "trojan.win32.schoolbus" ascii wide nocase
        $s4 = "backdoor.schoolbus" ascii wide nocase
        $s5 = "win32/schoolbus.rat" ascii wide nocase
        $s6 = "schoolbus.server" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Schoolbus (Trojan) Execution & Triage
id: 96d138ab-f99b-58fb-8289-e57d9e87932d
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Schoolbus 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/schoolbus
- 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.t1071_001
- attack.t1547_001
- attack.t1105
- attack.t1056_001
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_SCHOOLBUS_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Schoolbus 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 = "schoolbus" 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. Block inbound network connections to TCP port 2001 on perimeter firewalls.
2. Kill active Schoolbus server processes running from %SYSTEM32% or %TEMP% directories.
3. Delete persistence values under HKLM and HKCU Software\Microsoft\Windows\CurrentVersion\Run.
4. Conduct a full antimalware disk scan to eliminate secondary dropped dropper stubs.

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 downloaded from unverified peer-to-peer file sharing repositories or forum links.
2. Avoid operating compromised machines without performing full forensic memory triage.

References & External Analysis

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

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Ircbrute
• Synrat
• Infector_Ng_2004
• Coolvibes
• Z_Dem0N
• Bubbledock
• Ggpass
• Dyloader

Machine-readable

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