Cuckoo Stealer is a macOS-focused information stealer with remote-access functionality that has been distributed through social-engineering campaigns, particularly fake Homebrew installation pages and broader ClickFix-style lures. The malware relies on user-assisted execution through native macOS tools, allowing operators to bypass Gatekeeper protections without exploiting a software vulnerability. Campaigns have used counterfeit software-installation workflows and deceptive prompts to convince victims to run malicious shell commands, after which a second-stage payload is retrieved and executed.
Once active, Cuckoo Stealer collects a broad range of host and user data. Confirmed behaviors include theft of Safari bookmarks, cookies, and browsing history; collection of system information such as hostname, OS build, and username; discovery of installed applications; and staging of data from Safari, Notes, and Keychain prior to exfiltration. It has also been observed harvesting passwords through native-looking macOS credential prompts and transmitting stolen information to command-and-control infrastructure. The malware can determine victim geography through language settings and implements locale-based filtering to avoid infecting systems configured for several CIS-related locales.
Cuckoo Stealer uses defense-evasion and persistence mechanisms typical of modern macOS malware. It has copied itself and stolen data into hidden directories, renamed itself to resemble legitimate software, removed quarantine attributes, and established persistence through LaunchAgents that repeatedly execute the payload. Communications with command-and-control infrastructure have been observed over socket-based channels and encrypted HTTPS in reported campaigns. Documented remote capabilities include command execution, controlled exfiltration, rebooting, and self-removal, supporting characterization as both an infostealer and a lightweight RAT.
The malware has been associated with fake Homebrew malvertising and ClickFix-style campaigns active across 2024 through 2026, alongside other macOS stealers such as Atomic Stealer and SHub Stealer. Developer and enterprise macOS systems are especially attractive targets because the lures imitate common administrative and software-installation workflows, increasing the likelihood of successful credential theft, persistence, and theft of sensitive local application data.
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34 distinct techniques documented for this family, organized by ATT&CK tactic.
Initial commands leverage curl to fetch obfuscated payloads, which are piped directly into shell interpreters (bash/zsh), minimizing the disk footprint.
ClickFix variant that uses the applescript:// URL scheme to invoke the macOS Script Editor... This URL-encoded hyperlink runs a dual-track routine... while silently executing the curl command in the background to deliver an infostealer, bypassing Gatekeeper via user-coerced interaction.
The content repeatedly describes payloads, strings, configuration files, scripts, URLs, and binaries being obfuscated or encoded using Base64, XOR, RC4, AES, RSA, hex encoding, custom algorithms, and other methods across many malware families and threat actors.
Long-term access is secured via LaunchAgents and .plist files, often masquerading as legitimate system or software updaters.
The content repeatedly describes malware and threat actors decoding, decrypting, deobfuscating, or unpacking payloads, strings, configuration data, commands, and C2 responses prior to execution or use.
Bundlore prompts the user for their credentials. Calisto presents an input prompt asking for the user's login and password. Cuckoo Stealer has captured passwords by prompting victims with a "macOS needs to access System Settings" GUI window. Dok prompts the user for credentials. FIN4 has presented victims with spoofed Windows Authentication prompts to collect their credentials. iKitten prompts the user for their credentials. Keydnap prompts the users for credentials. Proton prompts users for their credentials. RedCurl prompts the user for credentials through a Microsoft Outlook pop-up. SILENTTRINITY's credphisher.py module can prompt a current user for their credentials. XCSSET prompts the user to input credentials using a native macOS dialog box leveraging the system process /Applications/Safari.app/Contents/MacOS/SafariForWebKitDevelopment.
Exfiltration efforts focus on high-value data, including ... messaging session tokens (Telegram/Discord)
Exfiltration efforts focus on high-value data, including browser credentials (Chromium/Firefox), macOS Keychains
Exfiltration efforts focus on high-value data, including ... macOS Keychains
The content repeatedly describes malware and threat actors collecting usernames, identifying logged-in users, running whoami/query user/quser, checking whether the current user is an administrator, enumerating user sessions, and gathering account details from compromised hosts.
The content repeatedly describes malware and threat actors obtaining lists of running processes, using utilities such as tasklist, ps, WMI, Get-Process, CreateToolhelp32Snapshot, EnumProcesses, and similar APIs/commands to enumerate active processes on victim systems.
The content repeatedly describes malware and threat actors collecting host details such as OS version, hostname, architecture, CPU, memory, BIOS, domain, language, and other configuration data; e.g., "APT41 uses multiple built-in commands such as systeminfo and net config Workstation to enumerate victim system basic configuration information."
The content repeatedly describes malware and threat actors listing files and directories, enumerating drives, searching for files by extension/name/path, retrieving file metadata, and browsing file systems (for example: "APT28 has used Forfiles to locate PDF, Excel, and Word documents during collection" and "cmd can be used to find files and directories with native functionality such as dir commands").
APT38 has collected browser bookmark information to learn more about compromised hosts, obtain personal information about users, and acquire details about internal network resources.
DarkGate queries system locale information during execution. Later versions of DarkGate query GetSystemDefaultLCID for locale information to determine if the malware is executing in Russian-speaking countries.
"Bazar can query the Registry for installed applications." / "BRONZE BUTLER has used tools to enumerate software installed on an infected host." / "LightSpy ... enumerate the Applications folder to collect the bundle name, bundle identifier, and version information..." / "Volt Typhoon has queried the Registry on compromised systems for information on installed software."
"Amadey does not run any tasks or install additional malware if the victim machine is based in Russia"; "DarkGate queries system locale information... determine if the malware is executing in Russian-speaking countries"; "Ragnar Locker checks... GetLocaleInfoW and doesn't encrypt files if it finds a former Soviet country"; "Saint Bot has conducted system locale checks..."
Avaddon checks for specific keyboard layouts and OS languages to avoid targeting Commonwealth of Independent States (CIS) entities... Bazar can perform a check to ensure that the operating system's keyboard and language settings are not set to Russian... Clop has checked the keyboard language using the GetKeyboardLayout() function... Ryuk has been observed to query the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Nls\Language and the value InstallLanguage.
Bundlore prompts the user for their credentials. Calisto presents an input prompt asking for the user's login and password. Cuckoo Stealer has captured passwords by prompting victims with a "macOS needs to access System Settings" GUI window. Dok prompts the user for credentials. FIN4 has presented victims with spoofed Windows Authentication prompts to collect their credentials. iKitten prompts the user for their credentials. Keydnap prompts the users for credentials. Proton prompts users for their credentials. RedCurl prompts the user for credentials through a Microsoft Outlook pop-up. SILENTTRINITY's credphisher.py module can prompt a current user for their credentials. XCSSET prompts the user to input credentials using a native macOS dialog box leveraging the system process /Applications/Safari.app/Contents/MacOS/SafariForWebKitDevelopment.
The content repeatedly describes adversaries and malware storing collected data, command output, credentials, archives, or files in local temporary folders, working directories, hidden directories, registry locations, recycle bins, or specific files prior to exfiltration.
Rather than allowing users to highlight and copy the install command, the page forces them to use a single Copy button. That restriction is purposeful: it enables the attacker to inject an extra hidden command into the clipboard, outside of what is shown to the user on the webpage, which downloads a malicious payload in parallel with the Homebrew installer.
ADVSTORESHELL exfiltrates data over the same channel used for C2... Agrius exfiltrated staged data using tools such as Putty and WinSCP, communicating with command and control servers... numerous malware and groups sent victim data, files, credentials, or host information over existing C2 channels.
1 indicator attributed across vendor reports, sandbox runs, and researcher write-ups. Full values are available in Mallory.
IPs, domains, and DNS infrastructure linked to this family.
25 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A macOS infostealer used in ClickFix campaigns to exfiltrate sensitive user data from compromised systems.
Information stealer delivered via fake Homebrew pages that mimic the official install flow to trick users into installing malicious commands, enabling secret exfiltration and possible persistent access.
macOS infostealer/RAT delivered via typosquatted Homebrew-themed ClickFix lures; establishes LaunchAgent persistence, removes quarantine attributes, uses encrypted HTTPS C2, and steals browser credentials/session tokens, Keychain data, notes/messaging sessions, VPN/FTP configs, and data from numerous crypto wallet apps.
Second-stage macOS infostealer/RAT delivered via a ClickFix/Homebrew-typosquat paste-and-run command. Establishes LaunchAgent persistence, removes quarantine attributes, uses encrypted HTTPS C2 (X25519 ECDH-derived), supports remote command execution and file exfiltration, and steals high-value data including browser credentials/cookies, Keychain, Apple Notes, Discord/Telegram sessions, VPN/FTP configs, Steam sessions, and data from 20+ cryptocurrency wallets.
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Named campaigns wielding this family, with evidence pinned to each claim.
CVEs this family uses for access and lateral movement.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Every documented technique, ranked by evidence weight.
Reddit, Mastodon, and CTI community discussion around this family.