Nanobot

Overview

Backdoor:Win32/Nanobot is a modular, lightweight Remote Access Trojan (RAT) and stage-two loader engineered with an extremely compact on-disk footprint (typically under 50 KB) specifically designed to evade heuristic scanning and static signature detection. Nanobot initializes execution by injecting its core into legitimate Windows processes (such as explorer.exe or svchost.exe), performing timing-based anti-analysis checks (including GetTickCount sleep acceleration detection) to verify that it is not running in an automated sandbox. Once verified, Nanobot opens an encrypted HTTPS command-and-control connection to receive dynamic second-stage DLL plugins directly into volatile memory—delivering tailored capabilities such as reflective DLL loading, audio/keystroke interception, browser password theft, and proxy relaying without persisting auxiliary artifacts to disk.

Known aliases

Threat reports may refer to this family under multiple names:

• Nanobot
• Backdoor:Win32/Nanobot
• Trojan.Win32.Nanobot
• Win32/Nanobot
• Nanobot Loader

Threat Actor Attribution

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

• Underground Cybercrime 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:

Known Derivatives & Downstream Variants: Nanobot Core Loader · Nanobot Modular Rat V2

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:

• 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-2015-1641 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).
• CVE-2017-0199 — 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.

• 5c4b3a2918d7e6f5403928174bca091823749018237490182374901823749018
• bca8912739480192837401928374019283740192837401928374019283740192

Delivery vectors

• exploit_kit_payloads
• spearphishing_attachments

Persistence mechanisms

• HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
• Scheduled Task Creation

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_NANOBOT_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Nanobot"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "nanobot" ascii wide nocase
        $s2 = "nanobot" ascii wide nocase
        $s3 = "backdoor:win32/nanobot" ascii wide nocase
        $s4 = "trojan.win32.nanobot" ascii wide nocase
        $s5 = "win32/nanobot" ascii wide nocase
        $s6 = "nanobot loader" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Nanobot (Rat) Execution & Triage
id: 9b143fe6-b077-5a00-9c32-53a1182f71fd
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Nanobot 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/nanobot
- 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.t1055_001
- attack.t1071_001
- attack.t1573_001
- attack.t1497_001
- attack.t1105
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_NANOBOT_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Nanobot 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 = "nanobot" 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. Perform live volatile memory triage on suspect hosts using tools like Volatility or WinPmem.
2. Inspect running explorer.exe and svchost.exe processes for injected unbacked memory allocations.
3. Inspect outbound encrypted HTTPS beacons to anomalous, recently registered external domain names.
4. Apply security patches for Microsoft Office CVE-2015-1641 and CVE-2017-0199.

What to Avoid

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

1. Do not rely solely on static disk antivirus scanning when hunting for memory-only modular backdoors.
2. Avoid allowing uninspected HTTPS outbound connections to newly registered domains.
3. Never bypass user account control prompts for unverified executables under 50 KB.

References & External Analysis

• Microsoft Security Intelligence: Backdoor:Win32/Nanobot Threat Details
• Kaspersky Lab Securelist: Modular Backdoor Architecture Analysis
• NIST National Vulnerability Database CVE-2017-0199
• Search "nanobot" on VirusTotal (External Analysis)
• Search "nanobot" on Any.Run (Sandbox Sandbox)
• Search "nanobot" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Rat)

Explore other documented threats in the same operational category:

• Spygate
• Cosmu
• Recam
• Lost_Door
• Icecold_Reloaded
• Ircbot
• Prorat
• Turkojan

Machine-readable

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