This threat is associated with an activity group Microsoft tracks as Storm-0201. The following trojan arrives through a malicious macro-enabled Microsoft Word document contained in a ZIP file. The ZIP file is usually a malicious archive file containing large file sizes that can cause programs to crash.

Threat actors use zip bombs specifically to evade cloud-delivered antivirus features, by convincing users to locally download the malicious files to avoid detection by Microsoft’s recent macros disablement. 

Microsoft Defender Antivirus detects and removes this threat.

This threat uses an infected Microsoft Office file to download ransomware and other malware onto your PC.

It can arrive on your PC as spam email attachment, usually as a Word file (.doc).

As part of our continued efforts to tackle entire classes of threats, Office 365 client applications now integrate with Antimalware Scan Interface (AMSI), enabling Windows Defender ATP and other security solutions to scan macros and other scripts at runtime to check for malicious behavior. Learn how this integration exposes malicious intent even with heavy obfuscation: Office VBA + AMSI: Parting the veil on malicious macros.

Microsoft Defender Antivirus detects and removes this threat.

This threat uses an infected Microsoft Office file to download ransomware and other malware onto your PC.

It can arrive on your PC as spam email attachment, usually as a Word file (.doc).

As part of our continued efforts to tackle entire classes of threats, Office 365 client applications now integrate with Antimalware Scan Interface (AMSI), enabling Windows Defender ATP and other security solutions to scan macros and other scripts at runtime to check for malicious behavior. Learn how this integration exposes malicious intent even with heavy obfuscation: Office VBA + AMSI: Parting the veil on malicious macros.