Microsoft recently rolled out the Windows 10 November 2019 update with minor changes and features. Now there’s an email about a fake Windows 10 “critical update” is circulating around. This email claims to be from Microsoft but it actually contains malware.
Discovered by Trustwave, this email targeting Windows 10 users carries the subject lines, “Install Latest Microsoft Windows Update now!” or “Critical Microsoft Windows Update”. The email also comes with an attachment which is disguised as the Windows 10 ‘critical’ update. The attachment contains a ‘.jpg’ file extension with a random file name and file size of 28KB. The executable file is actually a malicious .NET downloader which installs ransomware in the device.
According to Trustwave, this malware works by downloading a program called “bitcoingenerator.exe” from a GitHub account. This bitcoin generator contains a ransomware called ‘Cyborg’. Once the ransomware is inside the system, it will encrypt all the files and lock it with 777 extensions. Users whose systems have been hacked will see a file on their desktop with the title “Cyborg_DECRYPT.text”. This file contains instructions for recovering the files but for a price. The ransomware is quite dangerous as it can get hold of all your files saved in your system.
Windows 10 users who may have received such emails should ignore and delete them. These emails usually appear in the spam box but some could show up in the primary inbox as well. Note that Microsoft never sends emails for software updates. If there is any update for Windows 10 it will be available under ‘Updates & Security’ section from the settings menu. It is also advised to install a good antivirus protection in your system to prevent such incidents.