New SynkLoader malware pushed in Microsoft Teams phishing campaign

A previously unknown malware family dubbed SynkLoader is being distributed in Microsoft Teams phishing campaigns to steal credentials via a fake lock screen.

The attacker impersonates the target company's IT help desk, a tactic Microsoft highlighted earlier this year as increasingly common in multi-stage attacks.

Expel’s security researcher Marcus Hutchins explains that the attacks direct the victim to install a fake “PowerShell Cleaner” executable (.MSI) hosted in Microsoft Azure, making the download appear trustworthy.

Analysis of the malware showed "compile dates and file timestamps indicating it was first compiled and distributed around July 28, 2026."

The installer extracts a PowerShell script named cleaner.ps1 and a ZIP archive containing the Python framework, a malicious Python script, precompiled Python libraries, and several fake Microsoft runtime DLLs.