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Microsoft Security Intelligence
Published Sep 07, 2007 | Updated Aug 22, 2017

Storm Worm

Detected by Microsoft Defender Antivirus

Aliases: Win32/Pecoan (CA) W32/Nuwar@MM (McAfee) Win32/Nuwar (Microsoft)


Storm Worm, or Win32/Nuwar, refers to a family of Trojan droppers that install a distributed peer-to-peer (P2P) downloader Trojan. This downloader Trojan in turn downloads a copy of the email worm component of Storm Worm.
Storm Worm may download and install additional malicious software, thus manual removal is not recommended. To detect and remove this Trojan and other malicious software that may have been installed, run a full-system scan with an up-to-date antivirus product such as the Microsoft Safety Scanner ( For more information, visit
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