Antivirus firm Intego today reported that it has discovered a new variant of the "MACDefender" malware that ups the ante by not requiring an administrator password for installation.



From Mac Rumors:

The step is accomplished by installing the application only for the current user.Unlike the previous variants of this fake antivirus, no administrator's password is required to install this program. Since any user with an administrator's account - the default if there is just one user on a Mac - can install software in the Applications folder, a password is not needed. This package installs an application - the downloader - named avRunner, which then launches automatically. At the same time, the installation package deletes itself from the user's Mac, so no traces of the original installer are left behind.

  New 'MACDefender' Variant Installs Without Admin Password Requirement