Published Jan 09, 2008 | Updated Sep 15, 2017


Detected with Windows Defender Antivirus

Aliases: No associated aliases


VirTool:WinNT/Sinowal.A is a complex component associated with command and control functions and the advanced stealth features of the Win32/Sinowal family.
Win32/Sinowal is a family of password-stealing and backdoor trojans. These trojans may try to find a cryptographic certificate on the infected computer and install a certificate on the computer to mislead users in Secure Sockets Layer (SSL) Web transactions. Some Win32/Sinowal components may also use advanced stealth functionality, or try to perform certain operations from the context of a trusted process such as explorer.exe in order to bypass local software-based firewalls.
If you suspect that your system has been affected with this malware, you may need to write a known-good copy of the Master Boot Record back to the disk to prevent the malware's driver from being loaded on the next reboot. This can be accomplished by using the Windows Recovery Console.
Please see the following articles for further detail on using the Windows Recovery Console:
When the MBR has been successfully restored, run a full-system scan with an up-to-date antivirus product such as the Microsoft Safety Scanner ( For more information, see
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