All news with #defense evasion tag

🔍The Q2 2025 HP Wolf Threat Insights Report describes how threat actors are increasingly chaining living‑off‑the‑land (LOTL) tools and abusing uncommon file types to evade detection. Attackers hide final payloads inside images or use tiny SVGs that mimic legitimate interfaces, then execute code via native Windows processes like MSBuild. These methods leverage trusted sites and native binaries to bypass filters and complicate incident response.

🔍 Security researchers at LevelBlue Labs identified an open-source Remote Access Trojan, AsyncRAT, being deployed via a multi-stage, fileless in-memory loader that avoids writing executables to disk. Attackers gained initial access through a compromised ConnectWise ScreenConnect client, executing a VBScript which invoked PowerShell to fetch two staged .NET assemblies. The first-stage assembly decodes payloads into byte arrays and uses reflection to run the secondary assembly directly in memory, while operators disabled AMSI and tampered with ETW to evade runtime detection. Persistence was achieved with a scheduled task disguised as "Skype Update," and the RAT used an AES-256 encrypted configuration to connect to a DuckDNS-based C2.

🔍 Researchers uncovered a sophisticated fileless campaign that executes malicious code entirely in memory to deliver AsyncRAT. The attack began via a compromised ScreenConnect client and a VBScript that used WScript and PowerShell to download two payload blobs saved to C:\Users\Public\, which were never written as executables but loaded into memory via reflection. A .NET launcher (Obfuscator.dll) was used to orchestrate persistence, disable security logging and load the RAT, which exfiltrates credentials, browser artifacts and keystrokes.

🔒 Bitdefender tracked a Chinese APT intrusion that used a novel, fileless framework dubbed EggStreme to compromise a Philippines-based military contractor. The multi-stage toolkit injects code directly into memory, leverages DLL sideloading and abuses legitimate Windows services for persistence, and delivers a gRPC-enabled backdoor, EggStremeAgent, with extensive reconnaissance and exfiltration capabilities. Bitdefender advises limiting use of high-risk binaries and deploying advanced detection and response to detect living-off-the-land operations and anomalous behavior.

🛡️ Bitdefender attributed a campaign against a Philippines-based military contractor to a China-linked APT that deployed a previously undocumented fileless framework named EggStreme. The multi-stage operation begins with EggStremeFuel (mscorsvc.dll), which profiles systems, opens a C2 channel, stages loaders, and triggers in-memory execution of the core backdoor via DLL sideloading. EggStremeAgent functions as a central backdoor, injecting a session-specific keylogger (EggStremeKeylogger), communicating over gRPC, and exposing a 58-command toolkit for discovery, lateral movement, privilege escalation and data theft. An auxiliary implant, EggStremeWizard (xwizards.dll), provides reverse-shell access and resilient C2 options; Bitdefender warned that fileless execution and heavy DLL sideloading make detection and forensics difficult.

⚠️ Mandiant reports attackers are actively exploiting a leaked ASP.NET machineKey sample from old Sitecore deployment guides to carry out ViewState code-injection attacks that execute arbitrary .NET assemblies in server memory. The issue, tracked as CVE-2025-53690, affects multi-instance deployments of Sitecore XM, XP, and XC that used the static sample key, and may also impact some Sitecore Managed Cloud Standard container configurations. After initial access, adversaries deploy tools Mandiant calls WEEPSTEEL and EARTHWORM, escalate to SYSTEM, create administrative accounts, dump SYSTEM/SAM hives, and move laterally. Sitecore customers are advised to inspect environments for indicators of compromise, rotate and encrypt <machineKey> entries, and follow Microsoft ASP.NET ViewState guidance.

🔐 Barracuda researchers have detailed new link-obfuscation capabilities in the Tycoon Phishing-as-a-Service kit that hide malicious destinations from scanners and recipients. Observed techniques include URL encoding with '%20' invisible spaces, deceptive Unicode characters, hidden codes appended to links, redundant protocol prefixes, and subdomain manipulation. Attacks also incorporate a fake CAPTCHA stage and tools aimed at bypassing multi-factor authentication, enabling more effective email-based social engineering and evasion of traditional filters.

🚨 Check Point attributes a BYOVD campaign to the Silver Fox actor that leverages a Microsoft-signed WatchDog kernel driver (amsdk.sys v1.0.600) to neutralize endpoint defenses. The operation uses a dual-driver approach—an older Zemana-based driver on Windows 7 and the WatchDog driver on Windows 10/11—to terminate processes and escalate privileges. An all-in-one loader bundles anti-analysis checks, embedded drivers, AV-killer logic, and a ValleyRAT downloader to establish persistent remote access.

⚠️ A newly discovered campaign attributed to the Silver Fox APT abuses trusted Microsoft-signed drivers to bypass security protections and install a remote access tool. Check Point Research found attackers used the WatchDog driver (amsdk.sys) and an older Zemana-based driver to terminate antivirus and EDR processes, enabling deployment of ValleyRAT. Researchers observed loaders with anti-analysis, persistence, embedded drivers and hardcoded lists of security processes, and warn that timestamp edits can preserve valid signatures while evading hash-based detection.

🔍 In a recent Sophos report, unknown actors abused the open-source forensic tool Velociraptor to download and execute Visual Studio Code, enabling an encrypted tunnel to an attacker-controlled command-and-control server. The intruders used the Windows msiexec utility to fetch MSI installers hosted on Cloudflare Workers, staged additional tooling including a tunneling proxy and Radmin, and invoked an encoded PowerShell command to enable VS Code's tunnel option. Sophos warns that misuse of incident response tools can precede ransomware and recommends deploying EDR, monitoring for unauthorized Velociraptor activity, and hardening backup and monitoring processes.

🔒 Researchers demonstrated BadCam, a BadUSB-style attack presented at BlackHat that reflashes a webcam's firmware so a standard camera can act as a programmable HID device. The proof-of-concept targeted Lenovo 510 FHD and Lenovo Performance FHD models using a SigmaStar SoC, exploiting lack of cryptographic firmware verification and Linux USB Gadget support to present keyboard/network interfaces. Standard scans and OS reinstalls won't remove such implants, so organizations should apply firmware patches, USB control policies, and HID monitoring to mitigate the risk.

🔒 FortiGuard Labs has detailed a global phishing campaign that uses personalized HTML attachments and spoofed websites to deliver a custom loader, UpCrypter, which installs multiple remote access tools. The operation uses tailored lures—voicemail notices and purchase orders—embedding recipient emails and company logos to appear legitimate. The delivered ZIPs contain obfuscated JavaScript that runs PowerShell, fetches further payloads (sometimes hidden via steganography) and ultimately loads RATs such as PureHVNC, DCRat and Babylon, while UpCrypter checks for sandboxes, enforces persistence and can force reboots to hinder analysis.