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Poseidon

Poseidon is a name used for multiple distinct malware strains, most prominently a macOS-focused infostealer and a Go-based Mythic post-exploitation agent/backdoor for macOS and Linux.

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Poseidon

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Poseidon is a name used for multiple distinct malware strains, most prominently a macOS-focused infostealer and a Go-based Mythic post-exploitation agent/backdoor for macOS and Linux. The macOS infostealer variant is widely recognized as a fork of Atomic macOS Stealer (AMOS) and became one of the most active Mac stealers in late 2024. It targets browser credentials and cookies, password manager data, cryptocurrency wallets, VPN configurations, and other user secrets, and has been associated with malvertising, fake software installers, cracked-software lures, and social-engineering prompts that mimic native Apple dialogs to harvest credentials. Reported capabilities include theft of browser passwords and cookies, cryptocurrency wallet data, and other application secrets from both consumer and business Mac systems.

Separately, Poseidon is also the primary macOS agent for the Mythic C2 framework, written in Go and used as a full-featured post-exploitation backdoor. This Poseidon agent has been observed in supply-chain compromises and targeted intrusions, including deployment on macOS and Linux systems after initial access. Reported functionality includes beaconing, shell execution, file operations, process listing, screenshot capture, clipboard monitoring, keylogging, credential harvesting, persistence, and support for lateral movement. On macOS, persistence mechanisms have included LaunchAgent, LaunchDaemon, and Login Item techniques. The Mythic Poseidon agent has been referenced in operations involving developer and CI/CD environments, as well as activity attributed to Transparent Tribe/APT36 and other intrusion sets using Linux-oriented RAT workflows.

Because the same name is used for both an infostealer lineage and a Mythic backdoor agent, attribution and classification should be handled carefully in operational contexts. In current security reporting, the most commonly searched and recognized use of Poseidon in the macOS malware ecosystem is the AMOS-derived infostealer.

Capabilities

  • Credential Theft
  • Exfiltration
  • Keylogging
  • Lateral Movement
  • Persistence
  • Post Exploitation
  • Reconnaissance
  • Session Hijacking

Reported operators

Threat actors

2 named in public reporting
TraderTraitor

After gaining initial access to the developer's machine, attackers deployed MythicC2's Poseidon agent, a robust Golang-based payload offering advanced stealth and extensive post-exploitation capabilities for macOS environments.

Transparent Tribe

Tied together with six months of passive DNS, this is the fourth Linux-oriented RAT family APT36 has rotated through since mid-2024 (Poseidon → AresRAT → DeskRAT, alongside the parallel Windows CrimsonRAT track).

MITRE ATT&CK

Poseidon in ATT&CK

30 distinct techniques

Reporting

Research mentioning Poseidon

Jul 31
Malware News

CaptiveCrunch: Midnight Blizzard targets travelers worldwide for malware delivery and credential theft - Malware News - Malware Analysis, News and Indicators

Microsoft reported that social-engineering lures are increasingly being used to trick users into launching malware themselves, with the ClickFix technique emerging as a major delivery method across phishing, malvertising, and compromised websites. In ClickFix attacks, victims are shown fake CAPTCHA, verification, or repair prompts that copy malicious commands to the clipboard and persuade them to run them, often leading to fileless execution through LOLBins, obfuscated PowerShell, and follow-on payloads such as Lumma Stealer, DarkGate, Latrodectus, ScreenConnect, and AMOS. Microsoft said the technique has hit thousands of enterprise and consumer devices daily and is now supported by a growing underground market of ClickFix builder kits sold on criminal forums. Fresh activity shows the tactic continuing to evolve. A SmartApeSG campaign observed on compromised web traffic redirected victims to a fake human-verification flow that fetched an HTA downloader from deltaode[.]com, retrieved a ZIP archive, and abused DLL side-loading to launch an unidentified RAT that later communicated with 89.124.79[.]98 over TCP 443. Separately, Microsoft linked the CaptiveCrunch campaign to Storm-2945, a sub-cluster of Russia-linked Midnight Blizzard, which has manipulated DNS and HTTP traffic on hospitality and other captive-portal networks to redirect travelers to phishing pages and fake browser or OS updates delivering CornFlake and ChocoShell for credential theft and espionage, including theft of browser credentials, Microsoft 365 tokens, and Wi-Fi credentials.

Jul 31
Malware Traffic Analysis

Malware-Traffic-Analysis.net - 2026-07-31: SmartApeSG ClickFix campaign pushes unidentified RAT

Jul 21
Security Online Info

ClickLock Stealer: macOS Malware That Locks You Out

Researchers reported a new macOS infostealer dubbed ClickLock Stealer that tricks users into pasting a malicious bash command into Terminal through ClickFix-style pages masquerading as Cloudflare verification prompts. Group-IB said the malware has been active since at least late May and has targeted at least 100 users in 33 countries, with more than half of victims in Europe. Once launched, the malware downloads multiple payloads for browser credential theft, cryptocurrency wallet theft, Keychain theft, password manager and FileZilla credential collection, shell history harvesting, and backdoor installation, then exfiltrates the stolen data to a Telegram bot. Researchers also linked the campaign to LaunchAgent persistence and a backdoor called goyim derived largely from GSocket tooling. ClickLock does not rely on a software exploit or privilege escalation; instead, it abuses user execution and suppresses defenses by repeatedly killing visible applications and NotificationCenter, sometimes every 210 milliseconds, until victims enter their macOS password and approve Keychain access. Apple separately published guidance warning that scammers increasingly use websites, chat agents, messaging platforms, and email to socially engineer Mac users into pasting unsafe Terminal commands, and said macOS may warn or block commands and scripts associated with known malware. Apple said such alerts mean the Mac has not yet been harmed and advised users not to run untrusted commands or scripts unless they fully trust the source.

Jul 20
Macrumors

'ClickLock' Malware Coerces Mac Users Into Giving Up Passwords - MacRumors

Jul 20
Xakep

Стилер ClickLock для macOS завершает процессы, вынуждая жертву ввести пароль - Хакер

Jul 18
Cysecurity News

Group-IB Uncovers ClickLock macOS Malware Targeting Passwords and Crypto Wallets - CySecurity News - Latest Information Security and Hacking Incidents

Jul 17
Scworld

New macOS stealer uses social engineering and coercion | brief | SC Media

Jul 17
Techrepublic Com Security

ClickLock Mac Malware Can Disable Apps for Three Days

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