I’ve just posted a new installment of my Interesting Times column, after quite a hiatus. This time, I’m commenting on the recent MP3Concept Trojan flap. Here are some highlights:

…Let’s see what we have so far:

– You can name an application anything and have it show any icon you wish. Always could.

– You can code an application to do anything, even harmful or deceitful things.

– The Finder will always show if it’s an application – but it can’t protect you from misleading icons.

– If you download such an application over a browser, file types, resource forks, or folder structures won’t be properly preserved unless it’s in an encoded form such as .bin, .zip, .sit or .dmg.

– If you get such an application as an e-mail attachment, most attachment formats will preserve resource fork and file type, but most e-mail clients will present an alert when you double-click on an application that came in as an attachment.

– Nevertheless, if there’s a deceitful document icon and an enticing name the user may double-click on the application even if there’s no extension at all.

What can the user do, then? Standard cautions apply. Don’t download applications from unknown sources. Check data files in the Finder to see if the “kind” field says “Application”. Don’t trust file icons on downloaded files. Don’t double-click on files you’ve downloaded; either drag the file onto the application you want to use it with or use the “Open With” contextual menu (or my Zingg! contextual menu to open it in a specific application. Don’t trust antivirus programs either, as they will either give you too many false positives or a false feeling of security. Disable automatic unstuffing, unzipping or running of downloaded items.

…What could Apple do? Options are limited here. Recall that this is not a Finder or Launch Services bug, so there’s no obvious fix.

…Summing up, a “social engineering” trojan application is not a new concept, but now that attention has been called to it, we may begin to see malicious implementations of it, more’s the pity.

Read the whole article if you want more details…