Between a Rock and a Hard Link

Microsoft handling symbolic and hard links for sandboxed processes has changed, impacting exploitation of privileged file overwrites. Hard Links, not originally restricted in a sandbox, can still be exploited for sandbox escapes or system level privilege escalation. NTFS supports linking a single file to multiple names. Creating file symbolic links is difficult in sandboxed applications, making it useful to drop a file linking to another for privilege escalation. The command shell's "MKLINK /H" can create a hard link, but not to a file without write access