Intego Warns of Mac OS X Trojan Horse

October 31st, 2007 at 3:00 PM - News by John Martellaro

Intego warned of a new Trojan Horse on Wednesday that affects Mac OS X and has been found on several pornography Websites. The Trojan Horse installs a modification to the Macis DNS server that allows it to redirect Web requests to alternate servers, phishing sites. Personal data can then be stolen at the redirected site. However, a long series of poor decisions by the user is required for it to become active.

Intego described the process of infiltration as follows:

TMO notes that this is not a reportable security weakness in Mac OS X. Rather, it is a carefully orchestrated sequence of events that, while specific to Mac OS X, could be replicated on any other OS.

The installation, in fact, depends on a long series of catastrophic failures of judgment by the user. The user must download an unknown file from a pornography Website, have Safariis general settings set to "Open isafei files after downloading," and then enter an administrator password for the installation of an untrusted package.

There have been previous discussions of such destructive packages, for example, a disguised shell script that contains an "rm -rf" command, which would erase the useris disk when double-clicked. This falls in the same category.

Intego suggested that one way to protect against this is to buy their VirusBarrier X4. However, itis always good to have a well planned personal security policy for a Mac exposed to the Internet. That includes not double-clicking downloaded files or attachments unless they are trusted, and just say no to installers that ask for an administrator password unless you really trust the commercial software vendor and inspect a provided list of what will be installed and where. Trustworthy companies also supply de-installers in case something goes wrong. Finally, deselect that Safari General preference regarding the opening of isafei files -- if itis on. Itis wise to leave it deselected unless thereis a compelling reason not to.