The Microsoft Security Response Team can move very quickly.

The tech world exploded Thursday with the revelation that Lenovo had preinstalled an adware program called Superfish Visual Discovery on an unknown number of its consumer PCs, with the extra bonus of a local root certificate that posed a frightful risk to owners of the affected machines.

On Friday, Microsoft released the latest definitions for its Windows Defender software, which is included as a standard feature on all Windows 8.x PCs. The new definitions, which are installed automatically, detect and remove the offending app and the certificate.
Read more: Microsoft updates Windows Defender to remove Superfish infection | ZDNet