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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.

SANS Internet Storm Center · 6d agoMalware in the wild 2 sources1

Hackers Weaponize AI Safety Guardrails to Hide Malware From LLM-Powered Security Scanners

ESET says Russia-aligned actor UAC-0099 hid guardrail-triggering comments in VBScript to derail LLM-based malware scanners in Ukraine.

ESET researchers linked a technique named GuardBreaker to Russia-aligned threat actor UAC-0099 during an attack against an organization in Ukraine. The group embedded a safety-sensitive, weapon-related request in a VBScript comment so an LLM-powered analysis tool might interpret it as an instruction and refuse or truncate analysis before reaching the malicious code. The VBScript downloaded MATCHBOIL, a C#-based loader used by the group alongside MATCHWOK and DRAGSTARE. OWASP guidance recommends treating code comments and metadata as untrusted input, sanitizing it, and never treating an LLM refusal as a clean verdict.

GBHackersupdated · 4d agofirst · 5d agoThreat actor in the wild 3 sources1

China-Linked UNC3569 Exploited Sogou Input Method Flaw to Deploy GRAYRABBIT Backdoor

China-linked UNC3569 exploited a Sogou Input Method flaw to deploy GRAYRABBIT backdoor on Windows machines across East and Southeast Asia.

Gen Digital found that China-linked UNC3569, a hacker-for-hire group tracked by Google since 2021, exploited a flaw in Sogou Input Method's Windows sgbiz: link handler to reach a sandbox-disabled Chromium 80 build and exploit 2021's CVE-2021-38003 for code execution. The chain delivered GRAYRABBIT, a remote shell backdoor capable of file transfer and module loading, via a 7-Zip DLL sideloading trick gated on process count. Tencent fixed the handler flaw in April 2026 but the embedded browser remains outdated. Sogou has over 455 million monthly users and roughly 70% share of Chinese input methods.

The Hacker Newsupdated · 2d agofirst · 5d agoThreat actor in the wild 3 sourcesCVE-2021-38003