PAPERMILL Malware Campaign Abuses Signed Notepad++ to Deliver VenomRAT to Windows Users
JUMPSEC tracks PAPERMILL, a China-nexus phishing campaign using a signed Notepad++ binary, libcurl.dll sideloading, and Donut loaders to deploy VenomRAT against Indian tax-audit targets.
PAPERMILL delivers ISO disk images via tax-audit phishing emails that passed SPF, DKIM, and DMARC, containing a renamed Authenticode-signed Notepad++ executable and a malicious libcurl.dll that proxies curl functions while executing loader logic in DllMain. The chain uses Mark-of-the-Web bypasses, anti-sandbox sleeps, UAC elevation prompts, Registry persistence, and a Donut shellcode loader to reflectively load .NET VenomRAT v6.0.3 with HVNC and credential-stealing capability, with C2 at 154.36.188.201:4449. JUMPSEC assesses the campaign as China-nexus, financially motivated, and Silver Fox-adjacent rather than definitively Silver Fox-operated.
Hackers Use ClickFix Lures to Deploy MacSync Stealer and Bypass macOS Security.
ClickFix malvertising campaigns deliver MacSync, a macOS infostealer sold as MaaS that bypasses Gatekeeper via Terminal commands and steals credentials.
Threat actors use ClickFix social-engineering lures, SEO poisoning, and malvertising impersonating brands like Claude, ChatGPT, Zoom, and Docker to trick users into pasting curl-to-zsh commands into Terminal, evading Gatekeeper and notarization checks. The MacSync Stealer (formerly Mac.c, emerged April 2025, linked to developer 'Mentalpositive') is a 64-bit Mach-O stager with single-byte XOR string obfuscation that daemonizes, polls C2 with custom API-key headers, streams AppleScript payloads into osascript, and persists via fake LaunchAgents. It steals browser credentials, Keychain data, SSH keys, session tokens, and crypto wallets, exfiltrating archives in 10MB HTTP PUT chunks. Microsoft documented more than 30 related MacSync domains.
Microsoft Tracks MacSync Stealer by Its Behavior, Not Its Domains
Microsoft correlates over 30 rotating domains to track MacSync Stealer, which steals passwords, SSH keys, wallets and AWS credentials.
Microsoft Defender Experts tracked MacSync Stealer, a macOS information stealer, by analyzing recurring behaviors rather than individual domains, linking over 30 domains to the campaign. The infection chain uses the ClickFix social engineering technique, tricking victims into pasting commands in Terminal, then uses curl, AppleScript, and native macOS tools to deploy the payload. The stealer targets Keychain data, browser passwords and cookies, SSH keys, AWS credentials, Kubernetes configurations, and Ledger and Trezor wallet data, staging data before exfiltration via chunked HTTP PUT requests. RST Cloud identified rapid C2 infrastructure replacement after initial public disclosure.
Microsoft Links 30+ Rotating Domains to MacSync Stealer Infrastructure
Microsoft links 30+ rotating domains to the MacSync macOS infostealer, confirming active credential and file exfiltration through chunked HTTP PUT uploads.
Microsoft Defender Experts correlated 30+ domains with MacSync Stealer, requiring aligned endpoint and network behaviors (process ancestry, command-line patterns, /curl/, /dynamic?txd=, and /gate?buildtxd= paths, API-key headers, chunked HTTP PUT parameters) to link infrastructure. Execution begins from an interactive zsh session consistent with ClickFix social engineering, with curl retrieving and Base64/gunzip decoding the payload, followed by collection of Keychain data, browser credentials, SSH keys, AWS credentials, Kubernetes configs, and Apple Notes. Data is zipped to /tmp/osalogging.zip, chunked, uploaded via HTTP PUT, and artifacts are deleted afterward; the analysis builds on RST Cloud's May 8 findings and overlaps with Microsoft's earlier 250+ domain ClickFix campaign distributing MacSync and Atomic Stealer (AMOS).
SloppyRAT: A New Tool For Ransomware Attacks
Zscaler details SloppyRAT, a new DLL backdoor delivered via ClickFix lures that stages CastleLoader and CastleRAT ahead of ransomware attacks.
Zscaler ThreatLabz analyzed SloppyRAT, a DLL-based backdoor distributed via ClickFix lures that abuses finger.exe over TCP port 79 to download a batch script. The malware copies curl.exe to download IronPython 3.4.2 from GitHub and executes zlib-compressed Base64-encoded Python to deploy CastleLoader and CastleRAT, then reflectively loads SloppyRAT in memory. It hinders analysis using XOR stack-string obfuscation, a modified affine cipher with modulus 127, and 13 runtime-decrypted code blocks, while communicating with C2 over a reverse SOCKS channel.
ClearFake WebDAV infection chain delivers Amatera stealer, ZigCryptoStealer, and NetSupport Manager
Cisco Talos details ClearFake WebDAV chains delivering Amatera stealer to a Ukrainian government organization, with cryptocurrency and credential theft payloads.
Cisco Talos investigated DLL executions named 'verification.google' via WebDAV UNC paths at a Ukrainian government organization, tracking the actor as UAT-10820 and assessing with moderate confidence the activity is Russian and opportunistic rather than targeted. The infection chain uses ClearFake JavaScript injected via a Cloudflare Worker, EtherHiding storage on BNB Smart Chain contracts, and a ClickFix fake Google CAPTCHA prompt to deliver Amatera stealer. Secondary payloads differ by C2: one loader deploys ZigCryptoStealer with a Go reverse TCP proxy and a vulnerable driver that kills EDR, while the other installs an unauthorized NetSupport Manager with a Russia-based C2. Similar Amatera chains were separately documented by Malwarebytes and Blackpoint Cyber, but with no shared infrastructure.
Mirai Variant V3G4 Targets IoT Devices
Unit 42 tracked the Mirai variant V3G4 exploiting 13 vulnerabilities across IoT devices and servers from July-December 2022 to build a DDoS botnet.
From July to December 2022, Unit 42 observed three campaigns spreading V3G4, a Mirai botnet variant, by exploiting 13 vulnerabilities, including CVE-2022-26134 in Atlassian Confluence and CVE-2019-15107 in Webmin. The campaigns shared the same C2 domains containing the string 8xl9, nearly identical shell script downloaders, and the same XOR keys, suggesting a single threat actor. The malware brute-forces telnet and SSH credentials, terminates rival botnet processes via a stop list, and receives DDoS commands from its C2. Compromised servers and networking devices are absorbed into the botnet for further attacks.
UBoatRAT Navigates East Asia
Unit 42 discovers UBoatRAT, a new custom RAT targeting South Korean and video-game industry personnel, delivered via Google Drive with GitHub-based C2 and BITS persistence.
Unit 42 identified UBoatRAT, a new custom remote access trojan first found in May 2017, whose initial version used a public Hong Kong blog service and a compromised Japanese web server for command and control. The latest variants target personnel or organizations related to South Korea or the video games industry, are delivered through Google Drive, and masquerade as Microsoft Word, Excel, or folder icons. The RAT checks for virtualization software and domain join, retrieves its C2 address from a Base64-encoded string in a GitHub-hosted file, uses a custom XOR-encrypted C2 protocol, and maintains persistence via Windows Background Intelligent Transfer Service (BITS) jobs that survive reboots.