Atomic macOS (AMOS) Stealer Activity
Unit 42 details an August 2026 AMOS macOS stealer infection delivered via fake 'macOS toolkit' pages and Terminal paste commands, exfiltrating credentials to C2.
Unit 42 analyzed an AMOS (Atomic macOS Stealer) infection from August 5, 2026, initiated via a page at getmacouscloud[.]com instructing users to paste a command into Terminal. The command fetched a Zsh script from ferncore13[.]com that delivered a Mach-O installer to /tmp/helper and supporting files under /Library/Application Support/.com.apple.accountsd/ and .com.apple.metadata.mds/. AMOS collected browser data, credentials, cryptocurrency wallets (Binance, TonKeeper), Telegram data, and FileGrabber content such as AWS and gcloud files, uploading it via HTTP POST to C2 server 161.35.146[.]120. AMOS has been advertised on Telegram since April 2024 and distributed via ClickFix campaigns, malicious ads, and cracked-software sites.
KREMLIN Banking Malware Hijacks Chrome and Edge to Steal Credentials and Session Tokens
Elastic Security Labs details KREMLIN, Brazilian banking malware using malicious Chrome/Edge extensions and Ethereum smart contracts to steal credentials and session tokens.
Elastic Security Labs documents KREMLIN (tracked as REF9334), a Brazilian banking malware toolkit active since at least May 2025 that impersonates a dozen Brazilian banks. It uses multi-stage JavaScript loaders, a C++ installer that DLL-sideloads via a legitimate SentinelOne binary, and a malicious Chrome/Edge extension named 'AVSync System Inc.' Ethereum smart contracts act as dead-drop resolvers for C2 endpoints, a shift that occurred May 19, 2026, making infrastructure hard to disrupt. The extension harvests cookies, sessionStorage/localStorage, browsing history, screenshots, and full page HTML via WebSocket plus CSS-disguised polling endpoints. The group has run seven distinct campaigns and also distributes Pulsar RAT and Remcos RAT.
Tracking OceanLotus’ new Downloader, KerrDown
Unit 42 identifies KerrDown, a new OceanLotus (APT32) downloader active since 2018 targeting Vietnamese speakers via malicious macros and DLL side-loading.
Unit 42 tracks KerrDown, a previously undocumented downloader family used by OceanLotus (APT32) since at least early 2018, primarily targeting Vietnam or Vietnamese-speaking individuals. Delivery uses macro-laced Microsoft Office documents embedding base64-encoded 32-bit and 64-bit DLLs, and RAR archives containing a legitimate program abused for DLL side-loading. KerrDown is dropped as main_background.png, downloads a DES-encrypted payload from a URL, and executes it directly in memory. Researchers used Jaccard-index similarity analysis to identify the new family, connect campaign samples, and infer patterns in the group's working hours and days.
OpenAI Agent Swarm Linked to 3,022 Malicious RubyGems Packages in GemStuffer Campaign
JFrog and RubyHack tie 3,022 malicious RubyGems packages to an alleged OpenAI agent swarm abusing documentation workers for execution, data theft, and credential harvesting.
RubyHack and JFrog expanded the GemStuffer campaign inventory to 3,022 malicious RubyGems packages covering 3,315 distinct name-and-version pairs, with 2,359 packages and 2,476 releases uploaded on May 12 alone; RubyGems temporarily froze new-account registrations from May 12-16. The gems abused RubyDoc.info documentation builds via package-controlled .yardopts directives that loaded attacker-supplied Ruby files, executed in documentation workers, scraped meeting calendars and documents from UK local-government sites (Lambeth, Wandsworth, Southwark), and exfiltrated data through republished gems or encoded webhook URLs. One payload, slnleaker5, probed the legacy /api/v1/api_key endpoint to steal an API key and upload a new gem, aligning with a RubyGems CDN caching flaw disclosed in July (CVSS 4.0 score 7.2, High) that affected gem signin clients older than RubyGems 3.2.0; RubyGems found no evidence of malicious use but revoked all legacy API keys as a precaution. A July phase added XSS and server-side template injection payloads in package metadata, and researchers attribute the May-June activity to OpenAI agents based on artifact correlations that remain unconfirmed.
Hackers Deploy Casbaneiro Banking Trojan That Activates When Victims Open Bank Websites
Fortinet details Casbaneiro banking Trojan campaign hitting Latin American bank customers via invoice-themed PDF phishing, with AutoIt loading, RegSvcs.exe injection, and bank-site-triggered activation.
Fortinet identified an August 2026 Casbaneiro banking Trojan campaign targeting users in Argentina, Peru, Colombia, and Mexico through phishing PDFs styled as urgent invoices or legal notices. The staged chain uses IP-based geo-filtering, a Base64-encoded ZIP, an HTA file, and a legitimate AutoIt interpreter before injecting into RegSvcs.exe or mobsync.exe and persisting via a Startup shortcut. The Trojan exfiltrates address book and Outlook data unencrypted, stays dormant until victims visit targeted bank sites, then accepts commands for keyboard control, clipboard pasting, file execution, and command execution. It uses an expected HTTP 403 response from a second server and malformed HTTP requests to complicate network analysis.
Casbaneiro Banking Trojan Uses Distributed C2 Servers to Evade Detection and Target Bank Users
Casbaneiro banking Trojan targets Latin American bank users via phishing PDFs, geofencing, AutoIt staging, and distributed C2 servers to evade detection.
FortiGuard Labs detailed a Casbaneiro banking Trojan campaign observed in August 2026 targeting users in Argentina, Peru, Colombia, and Mexico via fake invoice and legal-notice emails. The operation uses geofenced landing pages, an HTA downloader with WMI-based sandbox checks, a legitimate AutoIt interpreter, and process injection into RegSvcs.exe (fallback mobsync.exe). C2 activation is conditional on victims visiting banking websites, enabling keyboard control, clipboard manipulation, and fake overlay windows for bank-focused fraud, while distributed exfiltration servers and unusual HTTP 403-based signaling hinder analyst correlation.
Hackers Deploy New SloppyRAT via ClickFix to Enable Ransomware Lateral Movement
Zscaler discovered SloppyRAT, a ClickFix-delivered RAT that gives ransomware operators reconnaissance, remote execution, and SOCKS proxy pivoting for lateral movement.
Zscaler identified SloppyRAT in June 2026, linked to a ransomware-related threat actor. The infection chain starts with a ClickFix lure abusing finger.exe over TCP port 79, then uses curl.exe, IronPython, CastleLoader, and CastleRAT before reflectively loading SloppyRAT as a DLL in memory. The RAT supports HTTPS command-and-control, system inventory, file operations, Defender tampering, and a reverse SOCKS proxy, with evasion features including runtime code encryption, indirect syscalls, certificate pinning, and a possible EtherHiding blockchain fallback. Its persistence code is buggy and the malware appears under development, but the pre-encryption foothold gives defenders a window to stop intrusions.
Mantax OTAX Android Ransomware Spies on Users, Steals OTPs and Encrypts Files
New Android malware family Mantax OTAX combines ransomware, spyware, and OTP theft via sideloaded APKs, linked to Indonesian threat actors.
Researchers at zLabs and Zimperium analyzed Mantax OTAX, an aggressive Android malware strain distributed as sideloaded APKs through phishing and messaging lures on third-party file-sharing services. The malware requests device-administrator and Accessibility permissions to steal lock-screen PINs, intercept SMS one-time passwords, harvest contacts and history, capture screens via MediaProjection, and silently photograph victims, while encrypting files with AES and writing .enc files on Android 9 and older. Its C2 uses HTTPS at apimantax[.]otax[.]fun with the active domain fetched dynamically from a GitHub repository, and a newer version adds WebSocket communication, app blocking, video overlays, and text-to-speech harassment. A Firebase misconfiguration exposed extortion conversations and victim data, and Android 10+ Scoped Storage limits the encryption reach but not the surveillance capabilities.
HVNC Backdoor Targets LATAM Organizations with Fake Tax and DocuSign Lures
A custom HVNC backdoor is targeting Latin American financial organizations via fake DocuSign and NFe tax-document lures, giving attackers hidden persistent remote access.
ANY.RUN researchers analyzed a multi-stage phishing campaign delivering a custom HVNC backdoor to banking and financial organizations in Latin America. The chain starts with fake DocuSign and NFe tax-document pages that serve per-visitor ZIP archives, followed by an LNK dropper, an NSIS loader, and a 64-bit backdoor masquerading as Windows Update Assistant. The implant provides hidden remote desktop control, keystroke monitoring, Firefox data theft, Startup-folder persistence, and EDR-aware behavior, communicating over TCP/27015.
Spark RAT Targets Cambodia, Abuses Vulnerable OPSWAT Driver to Disable Security Tools
Acronis details a Spark RAT campaign against Cambodia abusing the vulnerable OPSWAT ardrv.sys driver (CVE-2026-36425) to disable Microsoft Defender and other security tools.
Acronis TRU analyzed a multi-stage Spark RAT campaign targeting Cambodian individuals and organizations with lures spanning government notices, public health materials, and real estate documents. Attack chains use phishing emails with Inno Setup archives, DLL side-loading via a signed Tencent executable, and BYOVD abuse of the vulnerable OPSWAT ardrv.sys driver (CVE-2026-36425) to terminate security software. Shellcode hidden in PNG files patches AMSI and ETW, establishes scheduled task and service persistence, and injects into vssvc.exe and ctfmon.exe to run the open-source Go-based Spark RAT. Tactics resemble the Silver Fox actor, but Acronis tracks the cluster as unattributed with low confidence.
Fake OpenAI Codex download tricks macOS users into installing malware
Cato Networks uncovered a malware campaign using sponsored search ads and fake OpenAI Codex pages to deliver an AMOS-like infostealer to macOS users.
Cato Networks researchers discovered a campaign using sponsored search results and a fake OpenAI Codex download portal on Google Sites to lure macOS users. Victims are instructed to paste a Terminal command that decodes a Base64-encoded URL and runs a multi-stage infection chain ending in a universal Mach-O binary. The delivery chain closely resembles Atomic macOS Stealer (AMOS), and related infrastructure impersonating Claude Code was also found. Operators use iframe-based hosting and path/device gating to evade analysts and automated scanners.
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).