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MSRC

Malware

Microsoft addresses App Installer abuse

Thursday, December 28, 2023

Summary In recent months, Microsoft Threat Intelligence has observed threat actors leveraging social engineering and phishing techniques to target Windows OS users and utilizing the ms-appinstaller URI scheme. We have addressed and mitigated this malicious activity by turning off ms-appinstaller by default. Additionally, Microsoft has coordinated with Certificate Authorities to revoke the abused code signing certificates utilized by malware samples we have identified.

Customer Guidance for the Dopplepaymer Ransomware

Wednesday, November 20, 2019

Microsoft has been investigating recent attacks by malicious actors using the Dopplepaymerransomware. There is misleading information circulating about Microsoft Teams, along with references to RDP (BlueKeep), as ways in which this malware spreads. Our security research teams have investigated and found no evidence to support these claims. In our investigations we found that the malware relies on remote human operators using existing Domain Admin credentials to spread across an enterprise network.