Threats & Adversaries · Phishing / BEC
Observed victims include financial and healthcare organizations. The payload arrives as signed MSI and a sideloaded hostfxr.dll, fingerprints hosts, and uses DNS for C2.
1 source · Mar 9
BleepingComputer
Microsoft Teams phishing targets employees with A0Backdoor malware
Hackers contacted employees at financial and healthcare organizations over Microsoft Teams to trick them into granting remote access through Quick Assist and deploy a new piece of malware called A0Backdoor.
originalPart of the PlainSec briefing for 2026-03-10
Every edition of this story: Microsoft Teams phishing installs A0Backdoor in finance, healthcare