SNOWLIGHT Malware (macOS Dropper)

The SNOWLIGHT malware is a sophisticated macOS dropper that has become a growing concern in the cybersecurity landscape. Initially identified as part of a targeted campaign involving the threat actor UNC5174—a group believed to be working on behalf of the Chinese government—SNOWLIGHT operates quietly but effectively, laying the groundwork for more dangerous malware infections such as the VShell Remote Access Trojan (RAT).

This dropper malware is designed to initiate secondary infections and maintain persistence on compromised devices, turning seemingly benign Macs into control nodes for attackers. It connects to a Command-and-Control (C&C) server, manipulates environment variables, and introduces payloads such as Sliver, Cobalt Strike, and VShell. Its modular behavior means future iterations could carry even more powerful payloads or evasion techniques.

Let’s take a closer look at the critical details surrounding this macOS-specific cyber threat:

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SNOWLIGHT Malware Overview Table

Category	Details
Threat Type	Mac malware, Dropper, macOS virus
Detection Names	Avast: MacOS:Downloader-CH [Drp] Combo Cleaner: Generic.MAC.Downloader.J.929FDCD9 ESET-NOD32: OSX/TrojanDownloader.Agent variant Kaspersky: HEUR:Trojan-Downloader.OSX.Agent.ao
Associated Emails	Not publicly disclosed (likely used in spear-phishing or fake software cracks)
Symptoms	No visible symptoms; malware runs silently in the background
Damage Potential	Identity theft, password/banking data theft, botnet recruitment, fileless in-memory infections
Payloads Dropped	VShell RAT, Sliver, Cobalt Strike
Distribution Methods	Malicious bash scripts, fake software cracks, phishing emails, malvertising
Danger Level	High – Enables multi-stage attacks and remote control
Known Threat Actor	UNC5174 (suspected Chinese contractor)
Removal Tool	SpyHunter Anti-Malware Tool

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The Role of SNOWLIGHT in Cyberattacks

SNOWLIGHT was not used as a standalone threat but rather as a second-stage dropper in a larger infection chain. The campaign began with a malicious Bash script, which introduced two payloads: one identified as dnsloger (the SNOWLIGHT dropper), and another named system_worker, associated with Sliver and Cobalt Strike—tools commonly used for exploitation and lateral movement within networks.

Once on a system, SNOWLIGHT performs a check for the existence of a temporary log file (/tmp/log_de.log). If it doesn’t exist, the dropper establishes a network socket to its C&C server, allowing it to receive additional instructions and payloads. These may include the VShell RAT, a fileless backdoor trojan capable of data exfiltration, remote control, and payload injection.

The malware also modifies system environment variables—an advanced technique often used to bypass detection or sandbox analysis. Additionally, it obfuscates communications to hinder forensic analysis.

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Why SNOWLIGHT Is So Dangerous

Unlike typical malware that manifests through visible issues like system slowdowns or pop-ups, SNOWLIGHT runs in stealth mode. Its fileless nature and in-memory execution of VShell make it difficult to detect through traditional antivirus methods. Once infected, users may experience no symptoms at all, even while their personal data is being harvested or their system is being used for other cyber operations.

Its modular design makes SNOWLIGHT particularly worrisome for security professionals. With each campaign, attackers can change the payloads or behavior of the dropper—making it a moving target in the cybersecurity space.

Manual Removal Steps

WARNING: Manual removal is risky. Only proceed if you’re confident with macOS internals.

Step 1: Quit Suspicious Processes

1. Open Activity Monitor (Applications > Utilities).
2. Search for unfamiliar or resource-heavy processes (e.g., AtomicStealer, MacStealer, etc.).
3. Select and click the “X” to force quit.

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Step 2: Remove Malicious Applications

1. Go to Applications folder.
2. Look for apps you didn’t install or that appeared recently.
3. Drag them to the Trash, then empty the Trash.

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Step 3: Delete Launch Agents and Daemons

1. Open Finder → Go > Go to Folder…
2. Check the following locations for malicious .plist or .app files:javascriptCopyEdit~/Library/LaunchAgents/ /Library/LaunchAgents/ /Library/LaunchDaemons/ ~/Library/Application Support/ ~/Library/Preferences/ /Library/Application Support/
3. Remove anything suspicious (files with random names or unknown origin).

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Step 4: Check Login Items

1. Go to System Settings > General > Login Items.
2. Remove any suspicious items from “Open at Login”.

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Step 5: Reset Browsers (if hijacked)

Safari:

• Preferences > Extensions > Remove suspicious extensions
• Preferences > Homepage > Set to preferred homepage
• Clear History and Website Data

Chrome:

• chrome://extensions → Remove malicious extensions
• chrome://settings/reset → Reset settings to default

Firefox:

• about:addons → Remove unknown add-ons
• about:support → Click “Refresh Firefox”

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Automated Removal (Recommended)

Manual removal may miss hidden components. For full cleanup and future protection, use a trusted anti-malware tool.

✅ Recommended Tool: SpyHunter for Mac

• Detects hidden Trojans, keyloggers, stealers, and malware droppers
• Removes all components, including launch agents and hidden scripts
• Prevents future infections with real-time protection

🔍 Download SpyHunter for Mac
Scan your Mac for threats and remove them automatically.

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Prevent Future Infections

• Enable System Integrity Protection (SIP) and Gatekeeper
• Only install apps from the Mac App Store or verified developers
• Keep macOS and all apps updated
• Use a strong antivirus with real-time protection
• Never open suspicious email attachments or links
• Use a password manager and avoid reusing passwords

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Conclusion

SNOWLIGHT is more than just a nuisance—it’s a gateway for serious cyber threats on macOS devices. With ties to advanced persistent threat groups and a design that enables multi-stage, fileless infections, it underscores the evolving sophistication of modern cyberattacks.

Users must take this threat seriously, especially since visible symptoms may not be present. Whether you use your Mac for personal browsing or business operations, the presence of SNOWLIGHT can lead to severe privacy breaches, identity theft, and financial damage.

For reliable removal and protection, use a proven anti-malware tool like SpyHunter to scan and eliminate this threat.