This security update resolves a reported vulnerability in the Microsoft Antimalware Client. The vulnerability, if left unpatched, may allow elevation of privilege due to the pathnames used by the Microsoft Antimalware Client. An attacker who successfully exploits this vulnerability could execute arbitrary code and take complete control of an affected system. The attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. An attacker must have valid logon credentials to exploit this vulnerability. The vulnerability could not be exploited by anonymous users.