Redtail Payload Analysis [Guest Diary], (Wed, Sep 9th)
SANS guest analyst detonated a RedTail Linux sample from a DShield honeypot, finding process masquerading as php-fpm, monitoring-kill behavior, and a TCP listener.
A DShield honeypot captured multi-architecture RedTail Linux executables (ARM, ARM64, i686, RISC-V, x86-64) deployed via shell scripts. Dynamic analysis of the UPX-packed, statically linked x86-64 sample (SHA-256 63be5f38...d35e) in an isolated Ubuntu 24.04 VM on Proxmox showed it renamed its process via prctl(PR_SET_NAME), killed a filesystem-monitoring process, and opened a TCP listening socket while surviving processes posed as php-fpm or PostgreSQL-like workers. Differential memory images pre- and post-execution were captured from the hypervisor for forensics.
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.
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.
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.
Hackers Abuse Google CAPTCHA, WebDAV and BNB Smart Chain to Deploy Credential-Stealing Malware
Cisco Talos details ClickFix campaigns abusing fake Google CAPTCHA prompts, WebDAV and BNB Smart Chain to deploy the Amatera infostealer.
Cisco Talos identified a multi-stage campaign, first observed in April 2026 when a Ukrainian government organization executed a disguised DLL named verification.google from a WebDAV path. The chain combines ClearFake JavaScript injected via malicious Cloudflare Workers, EtherHiding payloads stored in BNB Smart Chain contracts, ClickFix social engineering, and WebDAV-hosted DLL loaders to deliver the Amatera (ACR Stealer) infostealer. The Amatera configuration contained over 400 collection entries targeting browsers, messengers, crypto wallets, password managers, FTP and VPN tools, hunting for .kdbx, .p12, .pfx and .pem files. The pf.ch branch deploys ZigCryptoStealer, an EDR-terminating vulnerable driver and Go-based reverse TCP proxies, while the verification.google branch installs NetSupport Manager, supporting moderate-confidence attribution of the UAT-10820 activity to a Russian actor.
Four REVSTEALER-Linked Modules Disable Windows Update and Defender to Run a Crypto Miner
Elastic documents four persistent REVSTEALER-linked tools (ProManager, WinUpdate, SoftManager, LockAppHost); LockAppHost disables Windows Update and Defender to run a crypto miner.
Elastic Security Labs identified four previously unreported executables tied to REVSTEALER, a commercial Windows infostealer sold since at least February 2026: ProManager, WinUpdate, SoftManager, and LockAppHost. LockAppHost abuses CMSTP for elevation, adds Microsoft Defender exclusions, disables five Windows Update services and 13 scheduled tasks, then hides a miner in legitimate Windows processes; other modules steal wallets, clipboard-swap crypto addresses, and turn victims into reverse proxies. The components share REVSTEALER tradecraft including packer, runtime function resolution, and Polygon smart-contract backup configuration (EtherHiding). Elastic's detection rule matched about 4,700 VirusTotal samples over the past year; distribution uses hijacked YouTube channels promoting game cheats and a fake 'Claude Opus 5 Free Desktop' app.
ThreatsDay: 296K IoT Botnet, 100+ Water Systems Targeted, SharePoint RCE Chain + 27 New Stories
Weekly ThreatsDay bulletin details a ShinyHunters-style social engineering hit on ReliaQuest, the 296,000-device Dysphoria IoT botnet, and several new malware families.
ReliaQuest confirmed a social engineering attack on August 22, 2026, in which an attacker used a fake SSO page and MFA push approval to gain brief view-only access to an identity dashboard, with tactics matching ShinyHunters, which has since listed the firm on its leak portal. The Shadowserver Foundation reported the Dysphoria botnet has compromised nearly 296,000 IoT devices for DDoS attacks and recently added residential proxy capability. Cisco Talos documented JWR, an operator-driven phishing-as-a-service framework linked to The Outsider that harvests credentials, identity documents, and 2FA codes over an encrypted WebSocket. New malware coverage includes the Octagon Android fraud bot ($1,400/month), the C2Looper Rust backdoor delivered via ClickFix, and the Aeternum loader that moved C2 to the Polygon blockchain.
ValleyRAT: When Legitimate Software Becomes a Malware Delivery Tool
Kaspersky details ValleyRAT delivered via trojanized QN Wallpaper using DLL sideloading, tied to Silver Fox and hitting 1,500+ users in China and India.
Kaspersky found a malicious installer abusing a modified version of the legitimate QN Wallpaper adware application to deliver the ValleyRAT backdoor via DLL sideloading of libcef.dll. The installer masquerades as DingTalk, Chrome or Tencent Meeting software, creates persistence, disables Windows Defender via the DisableAntiSpyware registry key, and loads AES-encrypted payloads. ValleyRAT collects keystrokes, clipboard contents and screenshots plus system details, can download additional modules, and resists removal by injecting into svchost.exe or marking its process critical. The campaign was detected over 100,000 times in 2026, affecting more than 1,500 users mainly in China and India, and is attributed to Silver Fox with both espionage and financial motives.
Kimwolf v7 Android Botnet Makes HTTP/2 DDoS Traffic Look Like Legitimate Browsing
New Kimwolf v7 Android botnet adds HTTP/2 DDoS floods with Chrome fingerprints and takedown-resistant ENS/Tor C2.
Palo Alto Networks Unit 42 discovered Kimwolf v7, an evolution of the Kimwolf/AISURU Android and IoT botnet first tracked in February 2026. The new version performs HTTP/2 floods mimicking Chrome browser fingerprints and uses Ethereum Name Service, Tor hidden services, and a local proxy for resilient C2. The botnet targets Android TV boxes via ADB on port 5555 and offloads propagation to an external loader.
Kimwolf v7 Hides DDoS Traffic Behind Chrome Fingerprints and Ethereum
Unit 42 details Kimwolf v7, an Android TV botnet upgrade using HTTP/2 Chrome-fingerprint DDoS floods and Ethereum ENS-based C2 across 1.8M+ infected devices.
Palo Alto Networks Unit 42 identified Kimwolf v7 on February 3, 2026, an upgrade to an Android TV botnet active since August 2025 and linked to the AISURU botnet, which has infected over 1.8 million devices. The new version adds an HTTP/2-based DDoS flood that mimics full Chrome browser fingerprints, consolidates 43 attack commands into 15 methods covering layers 3-7, and resolves C2 addresses via Ethereum Name Service using five hard-coded public blockchain RPC endpoints, backed by a Tor hidden service and a local proxy on 127.0.0.1:23075. It spreads through residential proxies to Android TV boxes with ADB enabled on port 5555 and masquerades as netd_service. The botnet is associated with the record 31.4 Tbps DDoS attack in November 2025.