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.
Exploring the Latest Mispadu Stealer Variant
Unit 42 found a new Mispadu infostealer variant targeting Mexican users via malicious .url files exploiting the SmartScreen CVE-2023-36025 bypass.
Unit 42 discovered a new variant of Mispadu Stealer, a Delphi-based banking trojan first reported in 2019, found while hunting for the Windows SmartScreen bypass CVE-2023-36025. The campaign uses crafted .url files referencing UNC network-share paths with an HTTP port (@80) that forces payload retrieval over WebDAV via rundll32.exe, avoiding SmartScreen warnings. Analyzed samples (~4 KB, compiled 2023-11-12) predate the CVE publication, and ZIP payloads were likely distributed as email attachments, primarily targeting users in Mexico.
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.
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.
New IoT Malware Uses Public Linux Exploits to Gain Root and Launch DDoS Attacks
Nozomi details KATARU, an IoT botnet that brute-forces Telnet, exploits public Linux kernel flaws for root access, and launches multi-protocol DDoS attacks.
KATARU, discovered after honeypot Telnet brute-force activity from a Vietnamese IP, downloads an ARM payload (vlxx.arm) and attempts privilege escalation by editing /etc/passwd or exploiting CVE-2026-46300 (Fragnesia), CVE-2026-43284 (Dirty Frag), and CVE-2026-31431 (Copy Fail). It combines Mirai-style TCP, UDP, ICMP, HTTP, QUIC and DNS floods with application attacks against Minecraft, FiveM, OpenVPN and WireGuard. The malware uses X25519 and ChaCha20-Poly1305 encrypted C2, unusually broad persistence across systemd, cron, init frameworks, and Android hooks, plus anti-debugging and decoy traffic to hinder analysis. Implementers copied x86 shellcode into the ARM binary and reused an RFC 7748 test-vector key, indicating low-quality but rapidly evolving commodity development.