A sophisticated PowerShell-based backdoor named TASK#STOMP has been discovered that specifically targets business documents while maintaining persistent remote access to compromised systems. The infection begins with VBScript execution, establishing persistence through scheduled tasks and startup folder entries. The malware deploys two primary PowerShell payloads that scan fixed drives for Word, PDF, PowerPoint, Excel, and archive files modified within the past year, excluding files larger than 500MB. It employs filesystem watchers for continuous collection of new documents. Additional capabilities include screenshot capture, Wi-Fi password theft, clipboard monitoring, and arbitrary command execution. The backdoor communicates with two command-and-control domains and uses compiled C helpers to bypass TLS certificate validation, enabling connections to servers with invalid certificates.
The Larva-24009 threat actor, also known as HeptaX, has been conducting phishing email campaigns since 2023, targeting Korean and global users to install malware. Active through 2026, the actor uses LNK files disguised as documents with topics like hospital surveys, blockchain, project proposals, and resumes to target enterprises. Upon execution, obfuscated PowerShell commands deploy backdoors and download additional scripts from command-and-control servers. The attack chain includes persistence mechanisms via Task Scheduler, remote access through QuasarRAT and UltraVNC, and information theft using NirSoft tools, custom keyloggers, and screenshot capabilities. The actor also creates backdoor RDP accounts and exfiltrates credentials, browser data, and user files. Version 2.1 of their Notifier malware utilizes Telegram API for status reporting. The campaigns demonstrate consistent tactics and infrastructure across multiple years of operation.
A North Korea-linked threat actor known as KONNI has been observed conducting a phishing campaign targeting software developers and engineering teams, particularly those with blockchain expertise. The campaign uses AI-generated PowerShell backdoors and targets a broader range of countries in the APAC region. The infection chain begins with a Discord-hosted link downloading a ZIP archive containing a PDF lure and a malicious LNK file. The LNK file deploys additional components, including the AI-generated PowerShell backdoor. The backdoor employs various anti-analysis techniques and establishes persistence through scheduled tasks. This campaign demonstrates KONNI's evolution in tactics and tooling, including the adoption of AI-assisted malware development.
