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Apple Updates Anti-Malware Definitions to Address Fake Flash Player Trojan


Fake Flash Player trojan installer

While things have been relatively quiet on the malware front for OS X since a raid on Russian payment processing firm ChronoPay appeared to have taken down MacDefender nearly two months ago, one new trojan horse did pop up earlier this month. As detailed by F-Secure, the trojan known as "OSX.QHost.WB.A" masquerades as a Flash Player installer but actually adds entries to a computer's hosts file to redirect users attempting to visit certain Google sites.
Once installed, the trojan adds entries to the hosts file to hijack users visiting various Google sites (e.g., Google.com.tw, Google.com.tl, et cetera) to the IP address 91.224.160.26, which is located in Netherlands.

The server at the IP address displays a fake webpage designed to appear similar to the legitimate Google site.
Search results on the fake Google pages actually lead to pop-up windows that load external content which was broken at the time of discovery but presumably consisted of advertisements of some sort. While the threat as implemented at the time of discovery was relatively mild, inexperienced users falling for the trojan could find themselves unaware of what had happened to their systems and how to fix the hijacked routing added by the malware.


Consequently, Apple earlier this week made its first significant addition to its "XProtect.plist" file since the spate of MacDefender variants surfaced in June. The XProtect.plist file contains malware definitions to enable users' systems to recognize and warn users of malicious downloads, a feature that debuted with Mac OS X Snow Leopard back in 2009.

The original anti-malware system required manual updates to account for new threats, and as such was updated only rarely by Apple as part of larger software updates. But with an Apple software update issued in response to the MacDefender threat earlier this year, Mac OS X systems are now able to make daily checks for updates to that file to ensure up-to-date protection against malware.

Top Rated Comments

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41 months ago
Let's get this out of the way right now : This is not an OS X virus.
Rating: 36 Votes
41 months ago
Awesome, I was not aware that it updated daily.

And yes, this is not a virus. This is malware.
Rating: 11 Votes
41 months ago
No, it's not a "virus". It's a trojan. You think it's good, but its bad. (heh... depending on if you think "flash" is "good").

A question I have though, is under what conditions should ANY software modify the hosts file? Should Apple even allow programs that have been granted administrative rights to alter the hosts file? There is only a very limited benvolent use case for such an action, and that very related to what they did here: some anti-ad or anti-spyware utilities modify a host file to redirect known ad-producing domains to a "safe" domain. I personally think any modification of the host file should be given a warning like this:

The program _____ is trying to update a core Mac OS X system file that is used to provide network connectivity. While online advertisement blocking programs may require legitimate use of this file, most others applications may represent an attempt to install malicious software onto your computer. Are you sure you want to allow program _____ to modify this file?

Rating: 9 Votes
41 months ago
Been out of the loop for 10 weeks and MacRumors is getting my up to speed fast. I love this site.
Rating: 8 Votes
41 months ago

That's why you need to disable flash. :p


This has nothing to do with Flash.
Rating: 8 Votes
41 months ago
Funny.... I updated Flash yesterday on my kids' Mac mini and I thought that writing a Trojan that masquerades as an update to Flash would be brilliant since Flash is updated so often and getting prompted that you need to update Flash to view a website is very common..... And then today, here it is.
Rating: 8 Votes
41 months ago
in order to prevent this from happening, maybe the best way is to ship flash player with mac os x. :D
Rating: 5 Votes
41 months ago

Funny.... I updated Flash yesterday on my kids' Mac mini and I thought that writing a Trojan that masquerades as an update to Flash would be brilliant since Flash is updated so often and getting prompted that you need to update Flash to view a website is very common..... And then today, here it is.


Hmm, what are you thinking about today?
Rating: 5 Votes
41 months ago

So this trojan, doesn't prompt you like a normal update correct? Cause there was a normal update for flash that was found threw software update. Or was that the trojan? The reason i ask is because I'm new to mac and I assumed that if i was able to find the update threw the software updater that it was safe. Or is this trojan just like a pc virus/malware where it will try and install after clicking a bad link or going to a bad site?

Software Update won't include updates for non-Apple apps. If you get the update notice from already installed software, that should be safe. If, however, you visit a website, like I did this morning, that says you need an updated version of Flash player, don't install it there. Instead, go to Adobe's site directly and download and install the player.

To download Flash player: http://get.adobe.com/flashplayer/
To find your currently installed version: http://www.adobe.com/software/flash/about/
Rating: 4 Votes
41 months ago

Its totally fine.
Just a Jailbreak program on his computer backing up his Cydia blobs


I think,...could be wrong


No, you are quite right, it's the firmware signing address for iPhones. This is completely inert, nothing to see there. AidenShaw is simply demonstrating a lack of knowledge and basic research skills. If this is not enough, check on the website that AidenShaw posted (www.saurik.com/id/12), and read why the address is in the hosts file.

Seeing as the original server is gone, no one has anything to worry about. Macrumours should really update the article to reflect that.
Rating: 3 Votes

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