9 posts
Backdoor.Mistic is a new stealthy backdoor deployed in cybercrime intrusions since April 2026, using DLL sideloading via legitimate MpExtMs.exe and masquerading as EndpointDlp.dll. It executes payloads in memory with a self-deleting kill switch, enabling long-term covert access. Mistic is likely linked to Woodgnat (aka KongTuke), an initial access broker whose ModeloRAT toolkit has been used in attacks delivering Qilin ransomware, connecting this backdoor to the broader ransomware ecosystem.
Unit 42 identified an active cyberespionage campaign by the Iran-nexus APT group Screening Serpens, targeting entities in the U.S., Israel, and the Middle East. The threat actor deployed two new RAT families, MiniUpdate and MiniJunk V2, utilizing advanced AppDomainManager hijacking and DLL sideloading to evade native .NET security mechanisms like ETW. The attacks rely on highly tailored social engineering lures, such as fake job portals and video conferencing updates, to initiate the infection chain and establish persistent command and control.
Kazuar is a sophisticated, modular P2P botnet attributed to the Russian state-sponsored actor Secret Blizzard. It utilizes a tripartite architecture (Kernel, Bridge, Worker) and a leader election mechanism to minimize external C2 traffic, relying on Mailslots, Window Messaging, and Named Pipes for internal communication and HTTP, WSS, or EWS for external C2.
FrostyNeighbor, a Belarus-aligned threat actor, has updated its toolset to target Ukrainian governmental organizations with a multi-stage compromise chain. The attack utilizes spearphishing with malicious PDFs that redirect to a RAR archive containing a JavaScript dropper, which ultimately deploys a Cobalt Strike beacon via the PicassoLoader malware following strict server-side and manual victim validation.
Microsoft's May 2026 Patch Tuesday release addresses 132 CVEs, including 29 Critical vulnerabilities and 14 with a CVSS score of 9.0 or higher. Key threats include a critical authentication bypass in the Microsoft SSO Plugin for Jira & Confluence, unauthorized RCEs in Windows Netlogon and DNS Client, and multiple Office RCEs exploitable via the Preview Pane.
A supply chain attack utilizing five malicious NuGet packages typosquatting Chinese .NET libraries has been discovered distributing a cross-platform infostealer. The malware leverages .NET Reactor and JIT hooking via module initializers to execute automatically upon assembly load, targeting credentials and cryptocurrency wallets across developer workstations and CI/CD pipelines.
Cisco Talos identified an intrusion campaign utilizing the CloudZ RAT and a novel plugin named Pheno to intercept SMS and OTP messages. The malware abuses the Microsoft Phone Link application's PC-to-phone bridge, allowing attackers to steal sensitive authentication data from local SQLite databases without deploying malware directly to the victim's mobile device.
The Canadian Centre for Cyber Security issued a daily digest highlighting two major security advisories. Notably, Microsoft released an out-of-band update to patch a critical elevation of privilege vulnerability (CVE-2026-40372) in ASP.NET Core, and GitLab released updates to address vulnerabilities across its Community and Enterprise editions.
Sekoia TDR details their methodology for automating .NET malware analysis, focusing on an obfuscated Covenant Grunt implant used by APT28. The researchers demonstrate how to programmatically decrypt strings and decompile code using pythonnet and dnlib, culminating in the release of RePythonNET-MCP, a tool that enables AI-assisted reverse engineering and configuration extraction.
