Atomicrat

Category: trojan · Aliases: OSX.AtomicRAT, Trojan.Atomic, Backdoor.AtomicRAT · Sample count (EMBER 2018): 1 · Enrichment: insufficient_information · Updated: 2026-07-01T16:37:00Z

Category: TrojanActor: Unknown / CybercriminalIndustry: Global / OpportunisticMotivation: Opportunistic

Overview

Executive Summary

AtomicRAT is a highly capable Remote Access Trojan (RAT) engineered to provide attackers with covert, persistent, and interactive control over compromised endpoints. While historically associated with macOS targeting, variants of AtomicRAT have evolved to target Windows environments as well, acting as a powerful espionage and data exfiltration tool for sophisticated threat actors.

Infection Vector and Technical Capabilities

AtomicRAT is primarily distributed via highly targeted spear-phishing campaigns. These campaigns often leverage socially engineered lures (e.g., fake job offers or urgent corporate communications) containing weaponized documents or deceptive ZIP archives. Upon successful execution, AtomicRAT focuses on establishing a deep, persistent foothold:

Covert C2 Communication: The RAT establishes a persistent connection to its command-and-control (C2) server. To evade network detection, it frequently utilizes encrypted communications over standard web ports (HTTPS/443) or leverages legitimate cloud infrastructure (like Telegram APIs or public cloud buckets) as a proxy.
Comprehensive Espionage: AtomicRAT provides the attacker with a vast array of surveillance capabilities. This includes full file system manipulation, real-time keylogging, periodic desktop screen capturing, and the ability to silently activate connected webcams or microphones.
Credential Harvesting: A primary objective is credential theft. The RAT actively scans for and extracts saved passwords from web browsers, cryptocurrency wallet files, and secure enclave/keychain data (on macOS).

Threat Assessment

An AtomicRAT infection is a critical security incident. The malware's extensive capabilities mean that the compromised endpoint is fully under the control of the attacker, leading to the immediate loss of intellectual property, compromised user credentials, and the high likelihood of lateral movement across the enterprise network.

Incident Response and Remediation

Immediate Isolation: Sever the affected machine's network connection immediately to halt the C2 communication and prevent active data exfiltration.
Forensic Memory Analysis: Because advanced RATs often attempt to hide their processes, perform memory forensics to identify the injected threads and extract the specific C2 configuration for enterprise-wide IOC blocking.
Comprehensive Credential Reset: Assume all credentials utilized on the infected machine, as well as any stored in browsers or password managers, are fully compromised. Initiate an immediate, organization-wide password reset for the affected user.

Known aliases

Threat reports may refer to this family under multiple names:

MITRE ATT&CK Techniques

This family has been observed using the following ATT&CK techniques: T1059 T1056.001 T1113 T1125

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.
T1113: Monitor for frequent or unauthorized screen captures or clipboard reads. Restrict background applications from accessing desktop APIs.
T1125: Restrict access to local camera or microphone APIs. Utilize endpoint protection that monitors hardware access.

Generated Detections (Boilerplate)

These YARA and Sigma rules are auto-generated based on the family name and aliases. They must be heavily tuned before deployment in a production environment.

YARA Rule

rule MALWARE_WIN_ATOMICRAT {
    meta:
        description = "Detects Atomicrat (trojan)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "atomicrat" ascii wide nocase
        $s2 = "osx.atomicrat" ascii wide nocase
        $s3 = "trojan.atomic" ascii wide nocase
        $s4 = "backdoor.atomicrat" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Atomicrat Activity
id: 4cb03fbd490f42433d4a5534deef2351
status: experimental
description: Detects generic indicators of the atomicrat malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*atomicrat*"
            - "*osx.atomicrat*"
            - "*trojan.atomic*"
            - "*backdoor.atomicrat*"
    condition: selection
level: medium

References & External Analysis

Search "atomicrat" on VirusTotal (External Analysis)

Frequently Asked Questions

How do I remove the Atomicrat Trojan from Windows?

Manual removal of Atomicrat is highly discouraged as it may leave persistence mechanisms intact. We recommend disconnecting the device from the internet and utilizing a professional incident response service or enterprise-grade EDR software to conduct a full forensic sweep.

Is Atomicrat a virus or a Trojan?

Atomicrat is classified as a Trojan. Unlike traditional viruses that infect files, modern malware like Atomicrat typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.

What are the main symptoms of a Atomicrat infection?

Symptoms of Atomicrat can include unexpected system slowness, unauthorized outbound network traffic to unknown IP addresses, disabled security software, and suspicious background processes running from AppData or Temp directories.

Related Families (Category: trojan)

Explore other malware families in the same category:

Protect Your Network Against Trojans

Want to prevent Atomicrat and similar threats from compromising your organization? Read our comprehensive defensive guide: Banking Trojan Protection.

Need help with an active incident? Published by the SystemHelpdesk team.

Machine-readable

Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/atomicrat.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.