"Remote Desktop Client" updated, but NOT installed
Not patching that software is the most insecure thing - so approve the update. All OS X ship with some version of the Remote Desktop Client but it is not enabled by default.

Secure your Mac if you don't want this by:


Turn on the firewall in the security preference pane
Open sharing preference pane and deselect Screen Sharing and Remote Management if they are checked.
Don't let people know your user name, short user name or password or re-use a password with another service that could get compromised and then be used to try that same password against your Mac.


It's not malware, but malware could be used to change the settings or snoop your password (key logger) or phish you to enter your username and password where it can then use it for bad purposes. Out of the box, you shouldn't be open to exploits due to Apple shipping the Remote Desktop Client on OS X.