twitter ios iconWe've been following for some time the story of the Flashback trojan that has been targeting Mac users by masquerading as a Flash Player installer but which has also been evolving to include increasingly sophisticated tactics for infecting users' computers.

Antivirus firm Intego now reports that Flashback's creators are using an interesting new tactic for communicating with machines infected by the trojan: Twitter. According to the report, Flashback is programmed to search Twitter for Tweets containing a unique 12-digit code that changes daily, with the malware's authors being able to issue commands to infected computers by posting from any number of Twitter accounts simply by including the appropriate code as a hashtag.

These hashtags aren’t as simple as, say, #Flashback or #MacMalwareMaster, but are seemingly random strings of characters that change each day. Intego’s malware research team cracked the 128-bit RC4 encryption used for Flashback’s code and discovered the keys to this system.

The hashtags are made up of twelve characters. There are four characters for the day, four characters for the month, and four characters for the year. [...]

So, for today, March 5, 2012, the hashtag would be #pepbyfadxeoa.

Intego is monitoring Twitter to look for any commands being issued using the hashtag codes, also noting that Flashback uses a number of different user agent strings in its web queries looking for the Twitter contacts, seeking to avoid detection and removal.

Top Rated Comments

GGJstudios Avatar
119 months ago
I just upgraded my gfs flashplayer last week ... What are the chances that it's this Trojan ?? How can I check?
Go to your /Users/yourusername/Library/ folder and look to see if you find any of these files:
~/.MacOSX/environment.plist
~/Library/LaunchAgents/com.apple.SystemUI.plist
~/Library/Preferences/perflib
~/Library/Preferences/Preferences.dylib
~/Library/Logs/swlog
If you don't have any of these files, you're not infected.

Your Library folders are hidden by default in Lion. To get to your /Library or /Users/yourusername/Library (also known as the ~/Library) folders in Lion, Launch Finder and click Go > Go to Folder and type: /Library or ~/Library

Here's how to avoid any question:
With my flash player I'm careful. I never click on a pop-up when it tells me it's out of date.

I go to Adobe's site and update there.
This is very important:
To repeat: the vendor has provided no actual evidence that such messages are happening.
In fact, while I may have missed it, I've seen no corroborating evidence supporting the recent reports coming from Intego. I haven't seen any other security firm confirming the presence of these variations, or the variation that supposedly installs itself without user intervention, as they also claim. Until such claims are proven by other companies, I'll continue to find Intego's claims suspicious, at best.

Generally speaking, these reports by security firms are little more than thinly veiled attempts to scare users into buying their security software, which you don't need. However, such reports can be useful reminders for users to continue to practice safe computing.
[LIST=1]
* Make sure your built-in Mac firewall is enabled in System Preferences > Security > Firewall


* Uncheck "Open "safe" files after downloading" in Safari > Preferences > General


* Uncheck "Enable Java" in Safari > Preferences > Security. Leave this unchecked until you visit a trusted site that requires Java, then re-enable only for your visit to that site. (This is not to be confused with JavaScript, which you should leave enabled.)


* Check your DNS settings by reading this (https://guides.macrumors.com/Mac_Virus/Malware_FAQ#Why_am_I_being_redirected_to_other_sites.3F).


* Be careful to only install software from trusted, reputable sites. Never install pirated software. If you're not sure about an app, ask in this forum before installing.


* Never let someone else have physical access to install anything on your Mac.


* Always keep your Mac and application software updated. Use Software Update for your Mac software. For other software, it's safer to get updates from the developer's site or from the menu item "Check for updates", rather than installing from any notification window that pops up while you're surfing the web.

That's all you need to do to keep your Mac completely free of any virus, trojan, spyware, keylogger, or other malware.

You don't need any 3rd party antivirus app to keep your Mac malware-free. Macs are not immune to malware, but no true viruses exist in the wild that can run on Mac OS X, and there never have been any since it was released over 10 years ago. You cannot infect your Mac simply by visiting a website, unzipping a file, opening an email attachment or joining a network. The only malware in the wild that can affect Mac OS X is a handful of trojans, which cannot infect your Mac unless you actively install them, and they can be easily avoided with some basic education, common sense and care in what software you install. Also, Mac OS X Snow Leopard and Lion have anti-malware protection (http://support.apple.com/kb/ht4651) built in, further reducing the need for 3rd party antivirus apps.
Mac Virus/Malware FAQ (https://guides.macrumors.com/Mac_Virus/Malware_FAQ)
Score: 8 Votes (Like | Disagree)
FloatingBones Avatar
119 months ago
The claim is interesting, but a quick search on Twitter doesn't show that #pepbyfadxeoa is actually being used by any program for anything. If the vendor's claim is true, they should be able to tell us a prior hashtag which shows actual nefarious activity.

We are still suffering from Adobe's lax attitudes for security around their products. All of the "Get Flash Player" and "Get Adobe PDF Reader" links that Adobe encouraged in the past have helped foster a lackadaisical attitude towards the clear risk of installing a trojan horse on machines. I will be happy as Flash on the WWW continues to fade into the sunset.

I think this uses twitter even if you don't use it personally, they are just using the open nature of the site as a means to communicate with the malware.
Bingo. If the trojan is actually using twitter as a conduit, it's probably using accounts that were embedded in the trojan. Blocking those would require the blocking of connections to twitter servers with something like Little Snitch (http://www.obdev.at/products/littlesnitch/index.html)
or outbound blocks in your network's firewall.

To repeat: the vendor has provided no actual evidence that such messages are happening. I see no evidence with todays hashtag.

One other note: the Twitter stream is a real cesspool these days. As far as I can tell, Twitter does nothing to automatically remove the 'bot accounts that send out Amazon Associates link-spam. They're also doing nothing to automatically censor accounts that send @mentions that spam the "adult" dating sites. Doesn't Twitter have any friends in the Valley who could help them keep the toxic pollution out of their stream?
Score: 7 Votes (Like | Disagree)
GGJstudios Avatar
119 months ago

Much like life, if you hang around in bars, you can come down with diseases.
So if you don't hang around in bars, you won't catch any diseases???
Score: 6 Votes (Like | Disagree)
FloatingBones Avatar
119 months ago
I'm always suspicious of anti-virus firms who seem to know very specific details of viruses/malware/trojans.

I'm even more suspicious when the claimed evidence doesn't pan out. To alter the slogan from that famous Wendy's commercial (//www.youtube.com/watch?v=Ug75diEyiA0):

Where's the tweets? :D
Score: 5 Votes (Like | Disagree)
mijail Avatar
119 months ago
I'm always suspicious of anti-virus firms who seem to know very specific details of viruses/malware/trojans.

Word, bro. And what about those pesky "doctors" who seem to know all about illnesses and bacteria and whatnot? Damned scientists!
(Fricking magnets, how do they work?)

----------

Then you can send a message to the hacker how dumb he was. With the same amount of work he had put into this malware he could have created an app and probably made some money.

You mean he has no bussiness plan for this?
Score: 4 Votes (Like | Disagree)
Amazing Iceman Avatar
119 months ago
Nasty!!

(I'm breaking my arm patting myself on the back for my non-involement with social media.)

I do feel bad for the majority of the world who does use social media...this is really lousy.

Much crap on social media, but a tremendous amount of good in places where free expression is only possible through Twitter, etc. It's a powerful tool for many in the world, and any sympathy I might have for certain hackers is totally absent in situations like this.

Well, don't over pad yourself. The infection doesn't come from Twitter, but from a fake Adobe Flash Installer. Twitter is only one of the many ways hackers use to communicate with the hacked Macs.
Score: 3 Votes (Like | Disagree)

Top Stories

siir apple event april 20

Siri Reveals Apple Event Planned for Tuesday, April 20

Tuesday April 13, 2021 12:04 am PDT by
Siri has apparently prematurely revealed that Apple plans to hold an event on Tuesday, April 20, where the company is expected to reveal brand new iPad Pro models and possibly its long-awaited AirTags trackers. Subscribe to the MacRumors YouTube channel for more videos. Upon being asked "When is the next Apple Event," Siri is currently responding with, "The special event is on Tuesday, April...
apple event spring loaded

Apple's 'Spring Loaded' Event Officially Announced for Tuesday, April 20

Tuesday April 13, 2021 9:04 am PDT by
Following an overnight leak by Siri, Apple today officially announced that it will be holding a special "Spring Loaded" event on Tuesday, April 20 at 10:00 a.m. Pacific Time at the Steve Jobs Theater on the Apple Park campus in Cupertino, California. As with all of Apple's 2020 events, the April 2021 event will be a digital-only gathering with no members of the media invited to attend in...
apple event hashflag

Twitter Hashflag for April 20 Apple Event Goes Live

Tuesday April 13, 2021 2:21 pm PDT by
Following the overnight Siri leak and subsequent announcement that Apple will hold a media event on Tuesday, April 20, a new Twitter hashflag has appeared to help provide visibility for the event on the platform. For the last several recent events, Apple has utilized hashflags, which are little icons next to hashtags on Twitter, as a way to market its events. The company first started the...
iphone12cameras

Kuo: 2022 iPhones to Feature 48-Megapixel Camera, 8K Video, and 6.1 and 6.7" Sizes With No 5.4" Mini Option

Tuesday April 13, 2021 10:45 pm PDT by
The upcoming 2022 iPhone lineup will feature two 6.1-inch devices and two 6.7-inch devices, with no mini-sized 5.4-inch iPhone, well-respected Apple analyst Ming-Chi Kuo said in a note to investors that was seen by MacRumors. Two of the iPhones will be high-end models and two of the iPhones will be lower-end models, similar to the current iPhone 12 lineup. Apple introduced the 5.4-inch...
macos catalina serial number

Apple Preparing Rollout of New Randomized Product Serial Numbers Ahead of 'Spring Loaded' Event

Wednesday April 14, 2021 2:08 am PDT by
Apple is advising its authorized premium resellers and dealers to prepare for new products with 10 and 12 digital serial numbers, days ahead of when it's expected to reveal a slew of new products. MacRumors previously reported that Apple plans to switch to randomized serial numbers for future products starting in early 2021. The company now seems to be preparing for that roll-out, telling...
duanrui iphone13 notch samples

More Leaked iPhone 13 Samples Show Smaller Notch, Repositioned Earpiece and Front Camera

Wednesday April 14, 2021 1:06 am PDT by
Leaker known as "DuanRui" has today shared an image of two iPhone 13 "film samples," which show the same rumored smaller notch design coming to the iPhone 13 series that we've seen from other sources. In past tweets, DuanRui has accurately leaked the correct names of the iPhone 12 models and an iPad Air 4 manual revealing its new design, so there's good reason to think this leak is credible, ...
Google maps feaure green

Google Maps App for iOS Finally Updated After Four Months

Monday April 12, 2021 10:03 am PDT by
Following the completed rollout of App Privacy labels for its App Store apps, Google today updated the Google Maps app for the first time in four months. Apple in December began requiring all new app submissions and app updates to include App Privacy labels, detailing the data that is collected by the app so consumers know what they're sharing. Google didn't begin implementing App Privacy ...
iPad Pro Mini LED

Mini-LED iPad Pro Expected at Apple Event on April 20 as Production Ramps Up

Tuesday April 13, 2021 9:53 am PDT by
Apple today announced that it will be hosting a virtual event on Tuesday, April 20 at 10 a.m. Pacific Time, and one of the new products expected to be unveiled at the event is a new iPad Pro with a Mini-LED display. In a brief snippet shared with paid subscribers, Taiwanese supply chain news website DigiTimes today reported that Apple supplier Ennostar has substantially improved its yield...
apple event particularly innovative article

Gurman: Apple's 'Spring Loaded' Event Won't Feature Anything 'Particularly Innovative'

Thursday April 15, 2021 1:30 am PDT by
Bloomberg's highly-respected Mark Gurman says that he expects nothing "particularly innovative" or "extraordinary" to launch at Apple's "Spring Loaded" event next week, Tuesday, April 20. Gurman made the remarks during an interview for Bloomberg Technology, in which he reaffirmed that Apple will launch a new 11-inch and 12.9-inch iPad Pro, with the higher-end model featuring a brand new...
spotify car thing 1

Spotify Announces the 'Car Thing' as its First Hardware Device

Tuesday April 13, 2021 7:03 am PDT by
Spotify has today announced its first hardware device, the "Car Thing," which is an in-car dash-mounted music and podcast player (via TechCrunch). Spotify is looking to provide a product for customers who want a "more seamless" and personalized in-car listening experience, especially in the large number of cars that do not support modern in-car infotainment systems. The Car Thing is aimed ...