SynkLoader: when you throw in everything but the kitchen sink

SynkLoader is a modular malware loader leveraging multiple programming languages (Python, C#, C++, PowerShell) to evade detection. Infection starts with a Microsoft Teams phishing campaign where attackers impersonate IT helpdesk personnel to convince targets to install a fake PowerShell cleaner via an MSI installer. The malware deploys memory-resident components that profile the system, establish persistence using scheduled tasks, and present a fake Windows lock screen to phish user credentials. It includes a reverse proxy module for network tunneling, allowing attackers to access internal corporate systems with stolen credentials. Remote shell and VNC modules enable hands-on-keyboard access. The multi-stage, multi-language approach and capabilities suggest possible ransomware deployment or initial access brokering.

The malware enables attackers to gain persistent access to compromised systems, steal user credentials via a fake lock screen, and tunnel into internal corporate networks. This access facilitates lateral movement, remote control, and potentially the deployment of ransomware or sale of access to other threat actors. The use of multiple programming languages and memory-resident components complicates detection and removal.

No vendor advisory or patch information is available for SynkLoader. Mitigation should focus on user awareness to prevent phishing, especially impersonation via Microsoft Teams, and blocking installation of unauthorized MSI packages. Endpoint detection and response solutions should be tuned to detect multi-language memory-resident loaders and suspicious scheduled tasks. Network monitoring for unusual reverse proxy or tunneling activity may help identify infections. Since no official fix exists, organizations should apply defense-in-depth controls and incident response readiness.