Microsoft to Windows administrators: Make sure all of your digital certificates have at least 1,024 bits. Internet Explorer won’t be able to access any website secured using an RSA digital certificate. Microsoft’s move reflects the relative ease with which digital certificates can now be cracked. The timing of Microsoft’s digital certificate spring cleaning has no doubt been driven by the Flame malware. The company recommends that IT administrators gain familiarity with it, and test any existing processes that might break, before it releases the update via Microsoft Update in October.”]
Source: https://www.darkreading.com/attacks-breaches/microsoft-warns-of-looming-digital-certificate-deadline