November 1st, 2007
Mac Attack: Porn video lures dropping DNS-changer Trojan
Organized identity thieves are using porn video lures to deliver malware to Mac OS X users, confirming fears among security researchers that it’s only a matter of time before Apple’s fast-growing platform becomes a big malware target.
The ongoing attack, first spotted by Intego, includes spammed links to Mac forums that point to free adult-themed videos. Clicking on the one of the videos pops up Web page that looks like this:
The site uses that pop-up to get users to download a disk image (.dmg) file disguised as a codec that’s required for viewing the video. If the Mac machine’s browser is set to to open “Safe” files after downloading, the .dmg gets mounted and the Installer is launched.
The target must click through a series of screens to become infected but once the Trojan is installed, it has full control of the machine.
According to anti-virus vendors, the Trojan is programmed to change the Mac’s DNS server, a trick used by phishers to load fake Web pages and hijack valuable user data.
Offensive Computing provides a walk-through of the risk scenario:
This Trojan horse, a form of DNSChanger, uses a sophisticated method, via the scutil command, to change the Mac’s DNS server (the server that is used to look up the correspondences between domain names and IP addresses for web sites and other Internet services). When this new, malicious, DNS server is active, it hijacks some web requests, leading users to phishing web sites (for sites such as Ebay, PayPal and some banks), or simply to web pages displaying ads for other pornographic web sites. In the first case, users may think they are on legitimate sites and enter a user name and password, a credit card, or an account number, which will then be hijacked. In the latter case, it seems that this is being done solely to generate ad revenue.
MacWorld provides step-by-step removal instructions. Techmeme discussion.
Ryan Naraine is a journalist and security evangelist at Kaspersky Lab. He manages Threatpost.com, a security news portal. Here is Ryan's full profile and disclosure of his industry affiliations.
For daily updates on Ryan's activities, follow him on Twitter.
Subscribe to Zero Day via Email alerts or RSS.
NT.
