Sdbot

Overview

SDBot is one of the most foundational, architecturally influential, and widely cloned IRC-controlled backdoor trojans in computer security history, first released in 2002 by an anonymous underground programmer. Written in modular C++, SDBot's source code was publicly disseminated across underground coding repositories, serving as the evolutionary ancestor and template for a sprawling lineage of 2000s-era worm and botnet threats—most notably Rbot, Agobot (Gaobot), and Spybot. SDBot connected compromised endpoints to secret Internet Relay Chat (IRC) channels, awaiting operator commands prefixed with passwords to launch distributed denial-of-service (DDoS) SYN floods, sniff local network traffic for plaintext credentials, log keystrokes, and automatically scan local subnets to exploit unpatched Windows RPC and SMB vulnerabilities (including MS03-026 / CVE-2003-0352 and MS04-011 / CVE-2004-0115). In 2007, SDBot and its derivatives were primary targets of the FBI's historic 'Operation Bot Roast', which dismantled multiple commercial botnet rings controlling over a million hijacked computers worldwide.

Known aliases

Threat reports may refer to this family under multiple names:

• SDBot
• SDbot
• Win32/SDBot
• Rbot
• Spybot
• Backdoor.SDBot

Threat Actor Attribution

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

• Anonymous Underground C++ Author (2002) / FBI Operation Bot Roast Indictments High confidence
  Basis: Released open-source in 2002. Targeted in the FBI's landmark 2007 Operation Bot Roast, which indicted commercial botnet operators in the US, Europe, and Asia for running massive SDBot/Rbot distributed denial-of-service swarms. [source]

Family Pedigree & Lineage

Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:

Known Derivatives & Downstream Variants: Sdbot V0.5B (Open Source Core) · Rbot Derivative · Agobot / Gaobot Branch · Spybot Variant

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:

• 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.

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-2003-0352 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).
• CVE-2004-0115 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).
• CVE-2008-4250 — 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.

• 0ba91fcf3b2a3dbe16999be3a6c4b2de0a34fe9a42f36d8f5b40cf392bc6914c
• 4de40ad749e7b2eb26d2466f10c66be91a134372a6b2cbdf7de0d6cfcf52240b

Delivery vectors

• Autonomous network worm exploitation over ports 135, 445, and 139 (MS03-026, MS04-011, MS08-067)
• Peer-to-peer file sharing networks disguised as cracked software utilities

Persistence mechanisms

• HKLM\Software\Microsoft\Windows\CurrentVersion\Run entries pointing to system executables
• Installation as a Windows service disguised as legitimate system background 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_SDBOT_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Sdbot"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "sdbot" ascii wide nocase
        $s2 = "sdbot" ascii wide nocase
        $s3 = "sdbot" ascii wide nocase
        $s4 = "win32/sdbot" ascii wide nocase
        $s5 = "rbot" ascii wide nocase
        $s6 = "spybot" ascii wide nocase
        $s7 = "backdoor.sdbot" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Sdbot (Rat) Execution & Triage
id: e215ec81-e61a-553c-b5f6-1b3453abbf67
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Sdbot malware family. Detects unauthorized persistence creation via Windows
  Registry Run keys, scheduled tasks, and privilege escalation indicative of RAT installations.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/sdbot
- https://malware-families-catalog.systemhelpdesk.com/defensive/backdoor-rat-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.rat
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1059_003
- attack.t1210
- attack.t1046
- attack.t1071_001
- attack.t1547_001
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \reg.exe
    - \schtasks.exe
    - \cmd.exe
    - \powershell.exe
    CommandLine|contains:
    - \CurrentVersion\Run
    - /create /tn
    - bypass -enc
    - net user /add
    - net localgroup administrators
  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_SDBOT_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Sdbot 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 = "sdbot" 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. Immediately isolate the compromised host from internal LAN and WAN environments to cut off interactive remote shell sessions established by Sdbot.
2. Inspect active socket listeners and outbound established network connections ('netstat -ano') to identify and sever covert TCP/UDP channels used by Sdbot.
3. Scan Windows Services, Scheduled Tasks, and Startup folders to locate and eliminate persistent backdoor listeners configured by Sdbot.
4. Invalidate all active VPN profiles, local administrator credentials, and session tokens that may have been harvested by the Sdbot operator.
5. Re-image the affected host using a validated golden image prior to reconnecting it to enterprise network segments.

What to Avoid

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

1. Do not attempt to interact with or send messages through the Sdbot remote terminal, as this alerts the attacker and may cause them to execute destructive anti-forensic commands.
2. Avoid relying solely on static file signatures, as Sdbot payloads frequently execute reflectively in memory without writing binaries to disk.

References & External Analysis

• FBI National Press Release - Operation Bot Roast
• CERT Coordination Center - SDBot/Rbot Family Analysis
• MITRE ATT&CK - SDBot
• Search "sdbot" on VirusTotal (External Analysis)
• Search "sdbot" on Any.Run (Sandbox Sandbox)
• Search "sdbot" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Rat)

Explore other documented threats in the same operational category:

• Prorat
• Recam
• Pcclient
• Rebhip
• Asyncrat
• Zegost
• Hav_Rat
• Lost_Door

Machine-readable

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