Threats Tagged 'anti-vm'

A previously undocumented Windows loader designated as OXLOADER delivers the CASTLESTEALER infostealer through malicious Google Ads campaigns, achieving remarkably low detection rates. The loader employs multiple obfuscation layers including control-flow flattening, opaque predicates, and mixed Boolean-Arithmetic techniques, along with self-modifying decryption stubs and abuse of the Windows .reloc section for shellcode staging. Distribution occurs via malvertising impersonating Node.js installations, redirecting victims through intermediary domains to Storj-hosted batch scripts. The loader implements five anti-VM and language checks, including CIS-region and Russian-language exclusions, suggesting a financially motivated Russian-speaking threat actor. OXLOADER uses DonutLoader to deliver the .NET-based CASTLESTEALER payload in memory, evading traditional detection mechanisms through deliberate engineering choices.

MediumMalwareUnited States#oxloader#donutloader#reloc section abuse

A sophisticated Python-based RAT targeting Korean users through spear phishing emails disguised as Microsoft security alerts. The attack chain employs LNK files embedded in ZIP archives, BAT-based obfuscation, and multi-stage loaders culminating in NarwhalRAT deployment. This advanced malware features keylogging, screen capture, microphone recording, and USB data collection capabilities. It utilizes a dual C2 infrastructure combining Korean relay servers (daehoat.com, novel21.co.kr) with pCloud API as a dead-drop resolver. The malware creates encrypted configuration files, implements anti-VM techniques, and establishes persistence through scheduled tasks. It operates as a manually-controlled RAT with selective function activation via C2 commands, employing in-memory execution to evade file-based detection.