Posts Tagged: f-secure


27
Aug 13

Who Wrote the Pincer Android Trojan?

Stories in this blog’s Breadcrumbs series have sought to comb through clues that point to the possible location and identities of malware authors and purveyors.  But from time to time those clues lead definitively back to an individual. In today’s post, we’ll talk with the author of  the Pincer Trojan for Android — a 32-year-old programmer at a mobile app development firm in Russia.

bwshadowIn April, Finnish security firm F-Secure  first warned about Trojan:Android/Pincer.A, which comes disguised as a security certificate and is designed to surreptitiously intercept and forward text messages. As F-Secure notes, previous malicious mobile apps pretending to be certificates have been mobile components of banking Trojans aimed at defeating two-factor authentication.

F-Secure researchers observed that Pincer used the IMEI of the victim’s phone as an identifier, and that the Trojan would call home to a control server and report the device’s phone and serial numbers, phone model, carrier and OS version. They also found that Pincer checks to see if it’s being run in a virtual environment, which is a common trick designed to frustrate malware analysis tools used by security researchers.

Interestingly, F-Secure noted that the code within the trojan includes a class called “USSDDumbExtendedNetworkService” — a component that was assigned a seemingly arbitrary variable that F-Secure researchers said was probably either associated with a French Canadian concrete company or the Twitter handle of a young Russian whose Google+ page lists employment as “Android developer”.

I followed up with F-Secure about this post, and learned that the redacted portion of that post — the variable included in that first variant of the Pincer Trojan — was “senneco.com” (Virustotal’s analysis lists it as “com.senneco”). A quick search on Google turns up Twitter and Google+ accounts by this name belonging to a Yuri Shmakov from Novosibirsk, Russia. Shmakov’s Google+ page says he is a developer at Arello-Mobile, a mobile app development firm also in Novosibirsk.

Text string "senneco" inside of the Pincer Android Trojan.

Text string “senneco” inside an early sample of he Pincer Android Trojan. Source: F-Secure.

A scan of Shmakov’s accounts turned up the email address senneco@gmail.com. I sent an email to that address, explaining F-Secure’s findings and asking whether the recipient had anything to do with the Pincer Trojan. To my surprise, Shmakov promptly replied that, why yes he had indeed created it as a freelance project.

Shmakov told me that, based on the client’s specifications, he suspected it might ultimately be put to nefarious uses. Even so, he completed the job and signed his work by including his nickname in the app’s code.

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15
Aug 13

Personalized Exploit Kit Targets Researchers

As documented time and again on this blog, cybercrooks are often sloppy or lazy enough to leave behind important clues about who and where they are. But from time to time, cheeky crooks will dream up a trap designed to look like they’re being sloppy when in fact they’re trying to trick security researchers into being sloppy and infecting their computers with malware.

A fake Nuclear Exploit Pack administrative panel made to serve malware.

A Nuclear Exploit Pack administrative panel made to serve malware.

According to Peter Kruse, a partner and cybercrime specialist with CSIS Security Group, that’s what happened late last month when a Twitter user “Paunchbighecker” started messaging security researchers on Twitter. Paunch the nickname of a Russian hacker who for the past few years has sold the wildly popular Blackhole exploit kit, a crimeware package designed to be stitched into hacked or malicious sites and foist browser exploits on visitors. The person behind Paunchbighecker Twitter account probably figured that invoking Paunch’s name and reputation would add to the allure of his scam.

The Paunchbighecker Twitter account appears to have been created on July 30 for the sole purpose of sending tweets to several security researchers, including this author, Mikko Hypponen of Finnish security firm F-Secure, French malware researcher Kafeine, Polish security researcher tachion24, and SecObsecurity. Strangely enough, the other Twitter account that received messages from this user belongs to Sauli Niinistö, the current president of Finland.

The link that Paunchbighecker sent to researchers displays what appears to be the back-end administrative panel for a Nuclear Pack exploit kit. In fact, the landing page was a fake merely made to look like a Nuclear pack statistics panel. Rather, embedded inside the page itself is a series of active Java exploits. 

Update, 1:56 p.m.: Security researcher Kafeine said he does not believe this was an attack against security researchers, but rather an intentional leak of badguy credentials.  Furthermore, Kafeine notes that visitors to the site link in the Twitter messages would have to take an additional step in order to infect their own computers.

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22
May 13

Krebs, KrebsOnSecurity, As Malware Memes

Hardly a week goes by when I don’t hear from some malware researcher or reader who’s discovered what appears to be a new sample of malicious software or nasty link that invokes this author’s name or the name of this blog. I’ve compiled this post to document a few of these examples, some of which are quite funny.

loginbetabot1

Source: Exposedbotnets.com

Take, for example, the login panel for “Betabot“: Attempt to log in to this malware control panel with credentials that don’t work and you’ll be greeted with a picture of this author, accompanied by the following warning: “Enter the correct password or I will write a 3-part article on this failed login attempt.”

The coders behind Betabot evidently have several versions of this login panel warning: According to a threat intelligence report being released tomorrow by RSA, the latest iteration of this kit uses the mugshot from my accounts at Twtter (follow me!) and Facebook (like it!).

As first detailed by Sophos’s award-winning Naked Security blog, the code inside recent versions of the Redkit exploit kit includes what appears to be a message blaming me for…well, something. The message reads: “Crebs, its [sic] your fault.”

sophosredkit

Text string inside of the Redkit exploit kit. Source: Sophos

The one I probably hear about most from researchers is a text string that is built into Citadel (PDF), an offshoot of the ZeuS banking trojan botnet kit that includes the following reference: “Coded by BRIAN KREBS for personal use only. I love my job and my wife.”

A text string inside of the Citadel trojan. Source: AhnLab

A text string within the code of the Citadel trojan. Source: AhnLab

Those are just the most visible examples. More commonly, if Yours Truly is invoked in the name of cybercrime, it tends to show up in malicious links that lead to malware. Here are a few just from the past couple of weeks:

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3
Apr 13

Who Wrote the Flashback OS X Worm?

A year ago today, Apple released a software update to halt the spread of the Flashback worm, a malware strain that infected more than 650,000 Mac OS X systems using a vulnerability in Apple’s version of Java. This somewhat dismal anniversary is probably as good a time as any to publish some clues I’ve gathered over the past year that point to the real-life identity of the Flashback worm’s creator.

mavookiconBefore I delve into the gritty details, a little background on this insidious contagion is in order. A keenly detailed research paper (PDF) published last year by Finnish security firm F-Secure puts the impact and threat from Flashback in perspective, noting that the malware boasted a series of “firsts” for its kind. For starters, Flashback was the first OS X malware to be “VMware aware” — or to know when it was being run in a virtual environment (a trick designed to frustrate security researchers). It also was the first to disable XProtect, OS X’s built-in malware protection program. These features, combined with its ability to spread through a then-unpatched vulnerability in Java made Flashback roughly as common for Macs as the Conficker Worm was for Windows PCs.

“This means Flashback is not only the most advanced, but also the most successful OS X malware we’ve ever seen,” wrote F-Secure’s Broderick Ian Aquilino.

The F-Secure writeup answers an important question not found in other analyses: Namely, what was the apparent intended purpose of Flashback? Put simply: to redirect Google results to third-party advertisers, all for the author’s profit. It’s name was derived from the fact that it spread using a social engineering trick of presenting the OS X user with a bogus Flash Player installation prompt. F-Secure notes that this same behavior — both the Flash social engineering trick and the redirection to fake Google sites that served search results for third-party advertisers that benefited the author — was also found in the QHost malware, suggesting that Flashback may have been the next evolution of the Mac QHost malware.

BLACK SEO

A year ago, I published a series that sought to identify the real-life hackers behind the top spam botnets. Using much the same methodology, I was able to identify and locate a young man in Russia who appears (and privately claims) to be the author of Flashback. As it happens, this individual hangs out on many of the same forums as the world’s top spammers (but more on that at another time).

Given Flashback’s focus on gaming Google’s ad networks, I suspected that the worm’s author probably was a key member of forums that focus on so-called “black hat SEO,” (search engine optimization), or learned in illicit ways to game search engines and manipulate ad revenues. Sure enough, this individual happens to be a very active and founding member of BlackSEO.com, a closely guarded Russian language forum dedicated to this topic.

Below is a screen shot taken from a private message between a “VIP” user named “Mavook” and a top forum member on BlackSEO.com. The conversation took place on July 14, 2012. A rough translation of their conversation is superimposed on the redacted screen grab, but basically it shows Mavook asking the senior member for help in gaining access to Darkode.com, a fairly exclusive English-language cybercrime forum (and one that I profiled in a story earlier this week).

BlackSEO.com VIP member "Mavook" claims responsibility for creating Flashback to a senior forum member.

BlackSEO.com member “Mavook” claims responsibility for creating Flashback to a senior forum member.

Mavook asks the other member to get him an invitation to Darkode, and Mavook is instructed to come up with a brief bio stating his accomplishments, and to select a nickname to use on the forum if he’s invited. Mavook replies that the Darkode nick should be not be easily tied back to his BlackSEO persona, and suggests the nickname “Macbook.” He also states that he is the “Creator of Flashback botnet for Macs,” and that he specializes in “finding exploits and creating bots.”

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4
Apr 12

Urgent Fix for Zero-Day Mac Java Flaw

Apple on Monday released a critical update to its version of Java for Mac OS X that plugs at least a dozen security holes in the program. More importantly, the patch mends a flaw that attackers have recently pounced on to broadly deploy malicious software, both on Windows and Mac systems.

Distribution of 550,000 Flashback-infected Macs. Source: Dr.Web.com

The update, Java for OS X Lion 2012-001 and Java for Mac OS X 10.6 Update 7, sews up an extremely serious security vulnerability (CVE-2012-0507) that miscreants recently rolled into automated exploit kits designed to deploy malware to Windows users. But in the past few days, information has surfaced to suggest that the same flaw has been used with great success by the Flashback Trojan to infect large numbers of Mac computers with malware.

The revelations come from Russian security firm Dr.Web, which reports that the Flashback Trojan has successfully infected more than 550,000 Macs, most which it said were U.S. based systems (hat tip to Adrian Sanabria). Dr.Web’s post is available in its Google translated version here.

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23
Nov 11

Apple Took 3+ Years to Fix FinFisher Trojan Hole

The Wall Street Journal this week ran an excellent series on government surveillance tools in the digital age. One story looked at FinFisher, a remote spying Trojan that was marketed to the governments of Egypt, Germany and other nations to permit surreptitious PC and mobile phone surveillance by law enforcement officials. The piece noted that FinFisher’s creators advertised the ability to deploy the Trojan disguised as an update for Apple’s iTunes media player, and that Apple last month fixed the vulnerability that the Trojan leveraged.

Image: spiegel.de

But the WSJ series and other media coverage of the story have overlooked one small but crucial detail: A prominent security researcher warned Apple about this dangerous vulnerability in mid-2008, yet the company waited more than 1,200 days to fix the flaw.

The disclosure raises questions about whether and when Apple knew about the Trojan offering, and its timing in choosing to sew up the security hole in this ubiquitous software title: According to Apple, as of June 2011, there were approximately a quarter billion installations of iTunes worldwide.

Apple did not respond to requests for comment. An email sent Wednesday morning to its press team produced an auto-response stating that employees were already on leave for the Thanksgiving holiday in the United States.

I first wrote about this vulnerability for The Washington Post in July 2008, after interviewing Argentinian security researcher Francisco Amato about “Evilgrade,” a devious new penetration testing tool he had developed. The toolkit was designed to let anyone send out bogus automatic update alerts to users of software titles that don’t sign their updates. I described the threat from this toolkit in greater detail:

Why is this a big deal? Imagine that you’re at an airport lounge, waiting to board your flight, and you pop open your laptop to see if you can hop on an open wireless network. Bear in mind that there are plenty of tools available that let miscreants create fake wireless access points for the purposes of routing your connection through their computer. You connect to that fake network, thinking you can check your favorite team’s sports scores. A few seconds later, some application on your system says there’s a software update available. You approve the update.

You’re hosed.

Or maybe you don’t approve the update. But that may not matter, because in some cases, auto-update features embedded in certain software titles will go ahead and download the update at that point, and keep nagging you until you agree to install it at a later date.

Evilgrade leveraged a flaw in the updater mechanism for iTunes that could be exploited on Windows systems. Amato described the vulnerability:

“The iTunes program checks that the binary is signed by Apple but we can inject content into the description as it opens a browser, with a malicious binary so that the user thinks its from Apple,” Amato said of his attack tool.

Emails shared with KrebsOnSecurity show that Amato contacted Apple’s security team on July 11, 2008, to warn them that the iTunes update functionality could be abused to push out malicious software. According to Amato, Apple acknowledged receipt of the report shortly thereafter, but it did not contact him about his findings until Oct. 28, 2011, when it sent an email to confirm his name and title for the purposes of crediting him with reporting the flaw in its iTunes 10.5.1 patch release details. Interestingly, Apple chose to continue to ignore the vulnerability even after Amato shipped a significant feature upgrade to Evilgrade in Oct. 2010.

The length of time Apple took to patch this significant security flaw is notable. In May 2006, I undertook a longitudinal study of how long it took Apple to ship security updates for its products. In that analysis, I looked at two years’ worth of patches issued to fix serious security bugs in Apple’s Mac OS X operating system, as well as other Apple software applications like iTunes. I found that on average, 91 days elapsed between the date that a security researcher alerted Apple to an unpatched flaw and the date Apple shipped a patch to fix the problem. In that study, I examined patch times for four dozen flaws, and the lengthiest patch time in that period was 245 days.

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21
Nov 11

DDoS Attack on KrebsOnSecurity.com

Last week, not long after I published the latest installment in my Pharma Wars series, KrebsOnSecurity.com was the target of a sustained distributed denial-of-service (DDoS) attack that caused the site to be unavailable for some readers between Nov. 17 and 18. What follows are some details about that attack, and how it compares to previous intimidation attempts.

The DDoS was caused by incessant, garbage requests from more than 20,000+ PCs around the globe infected with malware  that allows criminals to control them remotely for nefarious purposes. If you’ve noticed that a few of the features on this site haven’t worked as usual these past few days, now you know why. Thanks for your patience.

I shared the log files of the attack with Joe Stewart, director of malware research at Dell SecureWorks. Stewart discovered that the botnet responsible for hitting my site appears to have been created with Russkill, a commercial crimeware kit that is sold for a few hundred bucks on the hacker underground. Russkill, sometimes called Dirt Jumper, does its dirty work by forcing infected systems to rapidly request the targeted site’s homepage.

Stewart said he suspects — but can’t prove – that the control center for this botnet is noteye.biz, based on traffic analysis of Internet addresses in the logs I shared with him.

“I did not already have [noteye.biz] under monitoring so it is impossible to say for sure what targets were hit in the past,” Stewart wrote in an email. He noted that the same attacker also apparently runs a Dirt Jumper botnet at xzrw1q.com, which also is currently attacking Ukrainian news site genshtab.censor.net.ua, and kidala.info (“kidala” is Russian slang for “criminal,” and kidala.info is a well-known Russian crime forum).

“According to my logs this botnet did attack your site back in April, so this is some additional circumstantial evidence that suggests the noteye.biz [control network] may have been involved in the recent attack on your site,” Stewart wrote.

As Stewart notes, this is not the first time my site has been pilloried, although it was arguably the most disruptive. In October 2010, a botnet typically used to spread spam for rogue Internet pharmacies attacked krebsonsecurity.com, using a hacked Linux server at a research lab at Microsoft, of all places.

I’ve spoken at more than a dozen events this year, and the same question nearly always comes up: Do you ever get threatened or attacked? For the most part, the majority of the threats or intimidation attempts have been light-hearted.

Yes, occasionally crooks in the underground will get a bit carried away – as in these related threads from an exclusive crime forum, where I am declared the “enemy of carding;” or in the love I received from the guys at Crutop.nu, a major Russian adult Webmaster forum (the site now lives at Crutop.eu).

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28
Sep 11

Inside a Modern Mac Trojan

Mac malware is back in the  news again. Last week, security firm F-Secure warned that it had discovered a Trojan built for OS X that was disguised as a PDF document. It’s not clear whether this malware is a present threat — it was apparently created earlier this year — but the mechanics of how it works are worth a closer look because it challenges a widely-held belief among Mac users that malicious software cannot install without explicit user permission.

Image courtesy F-Secure.

F-Secure said the Mac malware, Trojan-Dropper: OSX/Revir.A, may be attempting to copy the technique implemented by Windows malware, which opens a PDF file containing a “.pdf.exe” extension and an accompanying PDF icon. F-Secure was careful to note that the payload installed by the dropper, Backdoor:OSX/Imuler.A, phones home to a placeholder page on the Web that does not appear to be capable of communicating back to the Trojan at the moment.

I wanted to understand a bit more about how this Trojan does its dirty work, so I contacted Broderick Aquilino, the F-Secure researcher who analyzed it. Aquilino said the sample is a plain Mach-O binary — which we’ll call “Binary 1″, that contains PDF file and another Mach-O binary (Binary2). Mach-O, short for Mach object, is a file format for executable files on OS X.

According to Aquilino, when you run Binary1, it will extract the PDF file from its body, drop it in the Mac’s temporary or “tmp” directory, and then open it. This is merely a decoy, as Binary1 continues to extract Binary2 from itself — also into the “tmp” directory — and then runs the file.

Upon execution, Binary2 downloads another binary from [omitted malware download site] and saves it as /tmp/updtdata. For the sake of continuity, we’ll call this latest file “Binary3.” Binary2 then executes and downloads the third binary, which opens up a backdoor on the OS X host designed to allow attackers to administer the machine from afar.

“All of this happens without the user needing to input their password,” Aquilino said.

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8
Aug 10

Foxit Fix for “Jailbreak” PDF Flaw

One of the more interesting developments over the past week has been the debut of jailbreakme.com, a Web site that allows Apple customers to jailbreak their devices merely by visiting the site with their iPhone, iPad or iTouch. Researchers soon learned that the page leverages two previously unknown security vulnerabilities in the PDF reader functionality built into Apple’s iOS4.

Adobe was quick to issue a statement saying that the flaws were in Apple’s software and did not exist in its products. Interestingly, though, this same attack does appear to affect Foxit Reader, a free PDF reader that I often recommend as an alternative to Adobe.

According to an advisory Foxit issued last week, Foxit Reader version 4.1.1.0805 “fixes the crash issue caused by the new iPhone/iPad jailbreak program which can be exploited to inject arbitrary code into a system and execute it there.” If you use Foxit, you grab the update from within the application (“Help,” then “Check for Updates Now”) or from this link.

Obviously, from a security perspective the intriguing aspect of a drive-by type jailbreak is that such an attack could easily be used for more nefarious purposes, such as seeding your iPhone with unwanted software. To be clear, nobody has yet seen any attacks like this, but it’s certainly an area to watch closely. F-Secure has a nice Q&A about the pair of PDF reader flaws that allow this attack, and what they might mean going forward. Apple says it plans to release an update to quash the bugs.

I’m left wondering what to call these sorts of vulnerabilities that quite obviously give users the freedom that jailbreaking their device(s) allows (the ability to run applications that are not approved and vetted by Apple) but that necessarily direct the attention of attackers to very potent vulnerabilities that can be used to target jailbreakers and regular users alike. It’s not quite a “featureability,” which describes an intentional software component that opens up customers to attack even as the vendor insists the feature is a useful, by-design ability rather than a liability.

I came up with a few ideas.

– “Apptack”

– “Jailbait” (I know, I know, but it’s catchy)

– “Freedoom”

Maybe KrebsOnSecurity readers can devise a better term? Sound off in the comments below if you come up with any good ones.

Finally, I should note that while Adobe’s products may not be affected by the above-mentioned flaws, the company said last week that it expects to ship an emergency update on Tuesday to fix at least one critical security hole present in the latest version of Adobe Reader for Windows, Mac and Linux systems.

Adobe said the update will fix a flaw that researcher Charlie Miller revealed (PDF!) at last month’s Black Hat security conference in Las Vegas, but it hinted that the update may also include fixes for other flaws. I’ll have more on those updates when they’re released, which should coincide with one of the largest Microsoft Patch Tuesdays ever: Redmond said last week that it expects to issue at least 14 updates on Tuesday. Update, Aug. 10, 5:06 p.m. ET:Adobe won’t be releasing the Reader update until the week of Aug. 16.


3
Aug 10

Anti-virus Products Mostly Ignore Windows Security Features

I recently highlighted a study which showed that most of the top software applications failed to take advantage of two major lines of defense built into Microsoft Windows that can help block attacks from hackers and viruses. As it turns out, a majority of anti-virus and security products made for Windows users also forgo these useful security protections.

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