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Posts tagged ‘tips’

3
May

Low Risk MACDefender Trojan is Easily Avoided

There have been widespread reports of people installing a trojan that masquerades as an anti-virus program dubbed MacDefender. When visiting a malicious or compromised website promoted by SEO (search engine) poisoning, some Mac OS X users using Safari are experiencing the automatic download of a disk image which then automatically mounts and launches an installer. Intego’s blog has a detailed report which shows that they’ve discovered instances of scareware, where the websites (ironically displaying a faux-Windows GUI) show a fake virus scan and inform the user that their computer is infected.

Note: The automatic mounting and execution of the installer can easily be prevented by unchecking the “Open ‘safe’ files after downloading” option in the Safari Preferences.

If the user installs it, the MacDefender app look very professionally done and is unlike any other OSX malware to date. It will periodically open porn sites, pop up warnings that the user’s computer is infected, and prompt them to purchase the MacDefender anti-virus software. The software purchase page is just a place to get the user’s credit card number, and no product is delivered.

For the most part this is a very low-risk trojan, and can easily be avoided by disabling the ‘safe files’ option, and not installing software that randomly appears on your computer. No website can arbitrarily scan your computer for malware, and if they tell you that you’re infected, they’re lying. If common sense and good security practice aren’t enough, you can install an anti-virus (eg. VirusBarrier or Sophos) that will pick up this trojan.

If you did accidentally install the trojan, it can be removed with the following steps:

  1. Open Activity Monitor (in /Applications/Utilities/), and find the MacDefender.app process in the list. If it’s there, select it and click ‘Quit Process’.
  2. Open System Preferences (in the Apple menu) and click on Accounts. Click on the Login Items tab for your user, and find MacDefender in the list. If it’s there, select it and remove it using the minus [-] button below the list.
  3. Delete MacDefender from your Applications folder.

Check out my article on Securing Leopard and Top 100 Security and Privacy Tips!

[Update 5/5/11] There are reports of variants of the MACDefender trojan going around under the name “Mac Security” or “Mac Shield”. For the reversers, check out this reverse engineering of the MACDefender binary.

25
Jan

Protecting and Recovering Your iPhone and iPad from Loss and Theft

My sister recently had her iPhone stolen, and it occurred to me that not enough people know how to help protect their iPhone/iPad from theft, what to do if it gets lost or stolen, and the steps to take even if they’re unable to get it back. Using a combination of security tips and geolocation, using Find My iPhone, you should have a much higher chance of recovering your device. Note that although this article is iPhone/iPad-centric… the principles apply to any smartphone!

NEW! Please refer to my Find My iPhone FAQ for the answers to some frequently asked questions (especially before asking a question in the comments). Read moreRead more

17
Jan

Insecurity: Bad Secret Questions and Information Disclosure

It’s a little known fact that most websites have a backdoor that can get you access in other people’s accounts – weak secret questions! Ok, so maybe it’s not a back door as such, but the threat is so high that for some websites it might as well be. Let me explain… Read moreRead more

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