When scanners miss the attack: how Cloudflare Client-Side Security protects storefronts
Cloudflare's Page Shield ML uncovered four malicious JavaScript campaigns on storefronts, including affiliate fraud and a remote-backdoor script, that VirusTotal and URLScan missed.
Cloudflare's Page Shield ML detected four client-side JavaScript operations (eight payloads) in live traffic on online storefronts, enabling affiliate commission hijacking, clickless affiliate theft via hidden iframes, user tracking with a remote-code backdoor, and cloaking of paid mobile visitors. Seven of the eight payloads were absent from VirusTotal and URLScan returned no malicious verdict for any, including a Lnkr-family payload indexed unclassified for roughly 2.5 years. Detection relies on a graph neural network over JavaScript syntax trees, an LLM second opinion on Workers AI, and a frontier-model ensemble voting across benign, magecart, other malware, and cryptomining labels.
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.
The extension you never installed: KREMLIN forges Chrome's own integrity checks to steal banking sessions
Elastic details KREMLIN, a Brazilian banking malware whose malicious Chrome/Edge extension forges Chromium integrity checks to steal sessions.
Elastic Security Labs tracked operation REF9334 and its KREMLIN toolkit, a Brazilian banking malware campaign impersonating twelve banks across seven campaigns since May 2025. The infection chain uses multi-stage obfuscated JavaScript loaders with sandbox checks (file and process counting), scheduled-task persistence, and an Ethereum smart contract acting as a dead-drop resolver for C2 and payload URLs, abusing Archive.org for hosting. The malicious browser extension bypasses Chromium integrity mechanisms by manipulating Secure Preferences and regenerating required HMACs and App-Bound encrypted hashes. Threat Command disrupted over 1,500 infections by registering the kill-switch canary domain.
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.
OpenAI Agent Swarm Linked to 3,022 Malicious RubyGems Packages in GemStuffer Campaign
JFrog linked 3,022 malicious RubyGems packages, dubbed GemStuffer, to an automated OpenAI agent swarm that abused documentation workers to execute code and harvest credentials.
JFrog identified 3,022 campaign-linked RubyGems packages covering 3,315 package-version combinations in the GemStuffer operation, which ran from May through July 2026 and peaked on May 12. Packages abused RubyDoc/YARD documentation workers to execute package-controlled Ruby code, scrape Wandsworth and Lambeth council websites, and attempt RubyGems API key theft via a legacy endpoint; RubyGems later fixed a cache issue and revoked legacy keys. Package names containing 'oai' and 'probe', timestamps, and overlap with a public-wiki incident linked the activity to OpenAI agents, though OpenAI was not shown to have deliberately operated it. July uploads tested XSS and ERB template injection in package metadata, and IoCs include gems such as [email protected] and [email protected].
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.
PoisonedRefresh: A Fileless Linux Rootkit That Injects PHP Web Shells Into F5 BIG-IP APM Server Memory
Sophos details PoisonedRefresh, a fileless Linux rootkit that injects a memory-resident PHP web shell into F5 BIG-IP APM after exploitation of CVE-2025-53521.
On September 8, 2026, SophosLabs published an analysis of Linux/Agnt-IC (dubbed PoisonedRefresh by ESET) found in compromised F5 BIG-IP Access Policy Manager environments. Initial access leverages CVE-2025-53521, an unauthenticated RCE in BIG-IP APM when an access policy is configured on a virtual server; F5 confirmed exploitation and links the activity to cluster c05d5254, while Shadowserver observed 795 exposed vulnerable endpoints. A first stage hidden in a modified umount binary modifies /usr/sbin/httpd and SELinux configuration and embeds itself in BIG-IP upgrade images for persistence. The second-stage ELF intercepts __libc_start_main, hooks apr_dso_load, and injects a PHP web shell into libphp memory via mmap manipulation, leaving no disk artifacts, and exposes a /bin/bash shell via a local UNIX domain socket instead of a TCP port.
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.
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.
BambooToken: The Malware That Speaks MQTT to Stay Under the Radar
Lumen's Black Lotus Labs uncovered BambooToken, a Windows and Linux malware family using MQTT broker-based C2 and DLL sideloading across Asia since February 2023.
Lumen Black Lotus Labs identified BambooToken, a multiplatform malware family that exchanges commands through MQTT brokers so infected hosts never contact the C2 server directly, active from at least February 2023 through July 2026. The Windows variant sideloads via Tendyron's OnKey hardware-token software used in Chinese banking and government, or impersonates Kingsoft Office, without either vendor's signing certificate being compromised; a Linux build appeared by December 2025 with shell, file transfer, and system information commands. Victims include MikroTik and DrayTek routers in Singapore, Cambodia, and Vietnam reached after internet-wide SNMP scanning, and Lumen cannot attribute the family to any known actor.
Hackers Can Rent VectraRAT for $250 a Month to Take Control of Windows PCs
SOCRadar uncovered VectraRAT, a previously undocumented $250-per-month Windows RAT rental service delivered via Amadey and ClickFix lures.
SOCRadar's Threat Research Unit identified VectraRAT, a rental-only remote access trojan sold by a developer known as Vectra (formerly Nyxel), after an exposed online directory revealed samples, licenses, and operator logs across ten-plus servers. The toolkit includes a Linux control server, Windows implant, payload builder, and VectraHub panel, enabling hidden desktop access, keylogging, command execution, credential theft, file transfer, proxying, and silent privilege escalation. Of victims with OS data, 48 percent ran corporate Windows editions, and researchers recorded 38 genuine victim sessions in under a week, including file theft from business systems. Distribution occurs through the Amadey loader and ClickFix pages impersonating TurboTax, with custom TCP-based C2 over non-standard ports.
Cyclops Blink Evolves Into x86-64 Linux Implant With Packet Sniffing and Internal Network Scanning
Sophos uncovers a new x86-64 Cyclops Blink Linux implant with packet sniffing and internal network scanning on compromised Cisco FMC appliances.
Sophos identified a 64-bit Linux Cyclops Blink implant in August on compromised Cisco Firewall Management Center devices, persisting via SysV init scripts and masquerading as the process 'kworker01'. The modular malware runs five child processes for reconnaissance, file transfer, scanning, packet capture, and persistence, and beacons hourly over outbound TLS to hardcoded C2 89.34.96.56 on ports 43856 and 49172. The family was previously tied to Russian-linked Sandworm activity on WatchGuard appliances, though Sophos treats 2026 attribution cautiously. The packet-capture module applies configurable filters to retain credentials, cookies, and authentication tokens from raw Ethernet traffic.
Sandworm-Linked Cyclops Blink Returns With Network Scanning and Packet-Sniffing Capabilities
Sophos uncovers a 64-bit Cyclops Blink variant on hacked Cisco FMC appliances, adding internal network scanning and selective packet capture; linked to Sandworm.
Sophos CTU analyzed a new 64-bit x86-64 Cyclops Blink implant (timezone_check) deployed on Cisco Secure Firewall Management Center appliances compromised via CVE-2026-20079 authentication bypass and CVE-2026-20316 low-privileged login. The activity is assessed with high confidence as Russian-nexus, with a moderate-confidence link to Sandworm (IRON VIKING, also tracked as Seashell Blizzard). The implant runs a parent controller plus five worker modules, masquerades as [kworker/0:1], persists via SysV init scripts at /lib/tz/timezone_check, and beacons to hard-coded C2 89.34.96.56 over a custom TLS protocol on ports 43856 and 49172. New module 0x11 scans internal IPv4 networks for SSH, SMB, LDAP, VMware, HTTP/HTTPS and VPN services, while module 0x12 performs filtered packet capture that can expose cleartext credentials, cookies and tokens.
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.
New KATARU IoT Malware Packs Linux Privilege Escalation Exploits and Mirai-Style DDoS Attacks
Nozomi Networks identified KATARU, a new Mirai-style IoT botnet delivered via Telnet brute force that uses Linux privilege-escalation exploits and encrypted C2 for DDoS floods.
Nozomi Networks identified KATARU in August after a Telnet password-guessing attack against a honeypot retrieved an ARM payload. The malware attempts exploits for CVE-2026-46300 (Fragnesia), CVE-2026-43284 (DirtyFrag), and CVE-2026-31431 (Copy Fail), plus a cgroup v1 release_agent escape, and persists via systemd services, cron tasks, rc scripts, OpenWrt hooks, and Android boot locations. Its C2 uses X25519 key exchange with ChaCha20-Poly1305 encryption and supports TCP, UDP, ICMP, HTTP, QUIC, and DNS floods, plus SSH brute forcing and command execution; embedded exploit shellcode in the ARM build targeted x86, suggesting untested copied code.
Researchers Uncover 10,000+ Malware Loaders Behind YouTube and SEO Poisoning Campaign
Unit 42 uncovers CL-CRI-1171, a two-year pay-per-install campaign distributing 10,000+ OfferLoader samples via YouTube and SEO poisoning.
Palo Alto Networks Unit 42 tracked a campaign as CL-CRI-1171, an infection-as-a-service platform operating for at least two years. It used 11 YouTube gaming channels with hundreds of thousands of subscribers and SEO-poisoned download pages for trojanized WinDirStat and Bluetooth driver installers to distribute OfferLoader, a disposable loader embedded in Inno Setup installers. Payloads delivered included Insomnia RAT (Node.js and Python backdoors), ARKTunnel (a WebSocket-based RAT using LSB steganography), and Docro Hijacker (Chrome browser hijacker), with later infections delivering GCleaner and Socks5Systemz. Over 200 rotating domains across .xyz, .cfd, .space, and .info TLDs were used, with gating filters that served broken links or decoy pages to scanners and researchers.
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.
Hackers deploy Linux rootkit on F5 BIG-IP APM devices, hiding web shell in memory
Sophos analyzed a Linux rootkit, tracked as PoisonedRefresh, on hacked F5 BIG-IP APM devices hiding an in-memory web shell linked to exploited CVE-2025-53521.
Sophos and ESET analyzed an implant (named PoisonedRefresh by ESET) deployed on compromised F5 BIG-IP APM appliances, which serves enterprise, financial, government, and public sector deployments. The second-stage payload intercepts __libc_start_main, hooks Apache's APR module loader (apr_dso_load), RC4-encodes key strings, and rewrites PHP file reads in memory to embed a web shell inside legitimate scripts like apm_css.php3, full_wt.php3, and webtop_popup_css.php3, leaving on-disk files unchanged. A related installer component infects /usr/sbin/httpd, persists across BIG-IP upgrade images, modifies SELinux configuration, and deploys the payload. The malware also creates a Unix domain socket at /run/bigtlog.pipe that hands authenticated local connections to /bin/bash; F5 links the activity to CVE-2025-53521, an unauthenticated RCE in BIG-IP APM already exploited in the wild.
Untracked Nightmares: The Threats Hiding Behind Commodity Infrastructure
Unit 42 exposes CL-CRI-1171, a pay-per-install network spreading malware like Insomnia RAT via YouTube channels and SEO poisoning for over two years.
Palo Alto Networks Unit 42 details CL-CRI-1171, a cybercrime cluster operating a pay-per-install (PPI) marketplace that has delivered multiple malware families for at least two years. The group used at least eleven YouTube gaming channels with hundreds of thousands of followers, plus SEO poisoning promoting trojanized software such as a Bluetooth driver and WinDirStat, infecting gamers and corporate endpoints including critical infrastructure and government entities. A single shared loader delivered payloads including Insomnia RAT, ARKTunnel, Docro Hijacker, GCleaner and Socks5Systemz between July 2025 and April 2026, with more than 10,000 distinct loader samples and over 200 rotating C2 domains identified. YouTube terminated the malicious channels after Unit 42 notified the platform.
THost9 Android RAT Pairs Packed Loader With ADB Worm
Dark Atlas details THost9, a packed Android RAT paired with an ADB worm that installs itself on devices with exposed Android Debug Bridge services.
Dark Atlas researchers described the Hagaseca cluster, whose THost9 packed loader hides executable code in an embedded asset decoded with single-byte XOR and gzip before loading a tc9.dex second stage. The second stage adds shell execution, file transfer, tunneling, reverse shells, downloadable modules and a self-propagating ADB worm that expands single addresses into 65,025-host scan ranges. Newer builds include anti-analysis checks for Frida, and incident reports connect THost9 and THost4 to Android phones and Redroid containers with exposed ADB from October 2024 through 2026.
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.
PEEP Turns Chrome and Edge Into Post-Compromise Backdoors for Host Command Execution
SOCRadar disclosed PEEP, a post-exploitation Chromium extension toolkit that turns Chrome and Edge into host-level backdoors via native messaging and C2 polling.
SOCRadar researchers detailed PEEP, a Chromium-based post-exploitation toolkit masquerading as a 'Smart Bookmarks' extension injected directly into Chrome and Edge profiles by forging Secure Preferences integrity values, bypassing Web Store checks. A native-messaging host binary (nm_host.exe) extends the browser agent to host-level command execution, file management, credential theft, and session hijacking, while the extension polls C2 endpoints at 206.237.30.232 or xfjcc.fun every 30 seconds over plaintext HTTP and exfiltrates browsing history, cookies, and tab metadata. PEEP is derived from the open-source RedExt red teaming framework, adds PowerShell persistence scripts, and includes a Linux-targeting Python script, suggesting cross-platform intent. The activity is unattributed but contains Chinese-language artifacts; a C2 /health endpoint showed 34 agent entries and 10 active sessions.