20 Mar South Korean 'Whois Team' attacks GReAT
15 Oct miniFlame aka SPE: "Elvis and his friends" GReAT
29 Aug What was that Wiper thing? GReAT
22 Aug 2nd Latin American Security Analyst Summit and threats around us Dmitry Bestuzhev
11 Jun Back to Stuxnet: the missing link Aleks
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Earlier today, reports of a number of cyberattacks against various South Korean targets hit the news.
The attackers, going by the handle “Whois Team” left a number of messages during the defacements:
You can read our Full Technical Paper on SPE / miniFlame here.
In May 2012, a Kaspersky Lab investigation detected a new nation-state cyber-espionage malware, which we named "Flame". Our research also identified some distinguishing features of Flame’s modules. Based on those features, we discovered that in 2009, the first variant of the Stuxnet worm included a module that was created based on the Flame platform. This confirmed there was some form of collaboration between the groups that developed the Flame and Tilded (Stuxnet/Duqu) platforms.
A more in-depth research conducted in June 2012 resulted in the discovery of another nation state-sponsored and previously unknown malware which we named «Gauss». Gauss used a modular structure resembling that of Flame, a similar code base and system for communicating with command-and-control (C&C) servers, as well as numerous other similarities to Flame.
In partnership with Symantec, ITU-IMPACT and CERT-Bund/BSI, we also published our analysis of the Flame Command and Control servers. The analysis showed that the code can understand several communication protocols to talk to different «clients» or malware:
In April 2012, several stories were published about a mysterious malware attack shutting down computer systems at businesses throughout Iran.
Several articles mentioned that a virus named Wiper was responsible. Yet, no samples were available from these attacks, causing many to doubt the accuracy of these reports.
Following these incidents, the International Telecommunication Union (ITU) asked Kaspersky Lab to investigate the incidents and determine the potentially destructive impact of this new malware.
After several weeks of research, we failed to find any malware that shared any known properties with Wiper. However, we did discover the nation-state cyber-espionage campaign now known as Flame and later Gauss.
It is our firm opinion that Wiper was a separate strain of malware that was not Flame. Although Flame was a highly flexible attack platform, we did not see any evidence of very destructive behavior. Given the complexity of Flame, one would expect it to be used for long-term surveillance of targets instead of direct sabotage attacks on computer systems. Of course, it is possible that one of the last stages of the surveillance was the delivery of a Wiper-related payload, but so far we haven-t seen this anywhere.
It was not a closed-door event; we had guests from 13 countries of the region including our panelists from law enforcement agencies who work every day in the fight against cybercrime:
What is Gauss? Where does the name come from? Gauss is a complex cyber-espionage toolkit created by the same actors behind the Flame malware platform. It is highly modular and supports new functions which can be deployed remotely by the operators in the form of plugins. The currently known plugins perform the following functions:
The modules have internal names which appear to pay tribute to famous mathematicians and philosophers, such as Kurt Godel, Johann Carl Friedrich Gauss and Joseph-Louis Lagrange.The module named “Gauss” is the most important in the malware as it implements the data stealing capabilities and we have therefore named the malware toolkit by this most important component.
|Variant||Path to project files|
|Dec 2011-Jan 2012||c:\documents and settings\flamer\desktop\gauss_white_1|
The Flame inside StuxnetFirst of all, let’s recap the Stuxnet story. We managed to recover just three different variants of the worm, created in June 2009, and in March and April 2010. The March 2010 variant was responsible for the greatest number of infections and was detected in June 2010 by specialists from the company VirusBlokAda in Belarus. This particular version was subjected to the most detailed analysis by anti-malware companies. Shortly afterwards, when news of Stuxnet had already become widespread, files related to its June 2009 incarnation were detected. This version, the so-called Stuxnet.A (1.0), differed considerably from the 2010 variants. The main differences were:
The Tocy storyIn October 2010, our automatic system received a sample from the wild. It analyzed the file thoroughly and classified it as a new Stuxnet variant, Worm.Win32.Stuxnet.s. With Stuxnet being such a big thing, we looked at the sample to see what it was! Sadly, it didn’t look like Stuxnet at all, it was quite different. So we decided to rename it to Tocy.a and thought “silly automatic systems!”. When Flame was discovered in 2012, we started looking for older samples that we might have received. Between samples that looked almost identical to Flame, we found Tocy.a. Going through the sample processing system logs, we noticed it was originally classified as Stuxnet. We thought, how was it possible? Why did the system think that this Flame sample was related to Stuxnet? Checking the logs, we discovered that the Tocy.a, an early module of Flame, was actually similar to “resource 207” from Stuxnet. It was actually so similar, that it made our automatic system classify it as Stuxnet. Practically, Tocy.a was similar to Stuxnet alone and to no other sample from our collection. Going back to the story, this is how we discovered the incredible link between Flame and Stuxnet.
The Flame malware uses several methods to replicate itself. The most interesting one is the use of the Microsoft Windows Update service. This is implemented in Flame’s “SNACK”, “MUNCH” and “GADGET” modules. Being parts of Flame, these modules are easily reconfigurable. The behavior of these modules is controlled by Flame’s global registry, the database that contains thousands of configuration options.
SNACK: NBNS spoofingThe SNACK module creates a RAW network socket for either all or pre-set network interfaces and begins receiving all network packets. It looks for NBNS packets of other machines looking for local network names. When such a packet is received, it is written to an encrypted log file (“%windir%\temp\~DEB93D.tmp”) and passed on for further processing. When a name in the NBNS request matches the expression “wpad*” or “MSHOME-F3BE293C”, it responds with its own IP address. If “SNACK.USE_ATTACK_LIST” variable is set to “True”, it also checks whether packets originate from IP addresses specified in its “SNACK.ATTACK_LIST” and responds to machines with these addresses. “Wpad” is a name used for automatic proxy detection. By responding to “wpad” name requests with its own IP address, the SNACK module announces the infected machine as a proxy server for its local network. SNACK and MUNCH also communicate with the GADGET unit that provides facilities for handling different events that come from other modules. The Flame’s registry contains LUA modules for processing events like “MUNCH_ATTACKED”, “SNACK_ENTITY.ATTACK_NOW”.
MUNCH: Spoofing proxy detection and Windows Update request“MUNCH” is the name of the HTTP server module in Flame. It is started only if “MUNCH.SHOULD_RUN” variable is set to “True” and there are no running programs that can alert the victim. These programs (anti-virus, firewalls, network sniffers etc.) are defined in the Flame’s registry in a list called “SECURITY.BAD_PROGRAMS” When MUNCH is started, it reads a buffer from the “MUNCH.WPAD_DATA” variable, replaces the pattern “%%DEFAULT%%” with the IP address of its best suitable network interface and waits for HTTP requests.
So, when a machine configured with automatic proxy detection tries to access one of the Windows Update hosts, it receives an IP address of the infected machine from SNACK, and then receives the IP address of the same machine as a proxy server from “wpad.dat” provided by MUNCH. From then, requests to the Windows Update service are passed through the MUNCH server.When a network client connects to the MUNCH server and requests an URI other than “/wpad.dat” and “/ view.php”, the server : 1) Runs “MUNCH.SHOULD_ATTACK_SCRIPT” – Lua script that checks if the User-Agent header matches at least one of the patterns specified in “MUNCH.USER_AGENTS.CAB_PATTERN_*”. The Flame registry files that we have contained the following patterns: MUNCH.USER_AGENTS.CAB_PATTERN_4 : WinHttp%-Autoproxy%-Service.*
“At the moment, we haven’t seen use of any 0-days; however, the worm is known to have infected fully-patched Windows 7 systems through the network, which might indicate the presence of a high risk 0-day.”
Our suspicion was heightened because fully patched Windows 7 machines were being infected over the network in a very suspicious manner.We can now confirm this is the main purpose of a special module of Flame called “Gadget” together with another module called “Munch”. (NOTE: It’s important to understand that the initial Flame infection could still be happening through zero-day vulnerabilities. The “Gadget” module is simply used to spread within a network from a machine that is already infected with the malware). The “Gadget” and “Munch” modules implement an interesting man-in-the-middle attack against other computers in a network. When a machine tries to connect to Microsoft’s Windows Update, it redirects the connection through an infected machine and it sends a fake, malicious Windows Update to the client. The fake update claims to be the following:
“update description="Allows you to display gadgets on your desktop."
displayName="Desktop Gadget Platform" name="WindowsGadgetPlatform">
This program (also detected as Worm.Win32.Flame.a), which is 28KB in size, has been signed by a fake Microsoft certificate:
This allows it to run in the victim’s machine without any warnings. The Flame “Gadget” downloader was compiled on December 27th, 2010. It was signed on December 28 and it was finally put into the CAB archive on Jan 11, 2011.
The following is exactly how the process occurs: the infected machine sets up a fake server by the name “MSHOME-F3BE293C”, which hosts a script that serves a full body of the Flame malware to victim machines. This is done by the module called “Munch”. When a victim updates itself via Windows Update, the query is intercepted and the fake update is pushed. The fake update proceeds to download the main body and infect the computer.
The interception of the query to the official Windows Update (the man-in-the-middle attack) is done by announcing the infected machine as a proxy for the domain. This is done via WPAD. To get infected, the machines do need however to have their System Proxy settings configured to “Auto”.As we continue our investigation of Flame, more and more details appear which indicate our initial statement: this is one of the most interesting and complex malicious programs we have ever seen. Important information: One June 4th, 2012, Microsoft released a number of blog posts and an Update for Windows which is blocking three fraudulent certificates used by Flame. We recommend that Windows users apply this update immediately. Microsoft SRD blog:http://blogs.technet.com/b/srd/archive/2012/06/03/microsoft-certification-authority-signing-certificates-added-to-the-untrusted-certificate-store.aspx Microsoft security advisory 2718704:http://technet.microsoft.com/en-us/security/advisory/2718704 MSRC blog:http://blogs.technet.com/b/msrc/archive/2012/06/03/microsoft-releases-security-advisory-2718704.aspx
On Sunday, May 27 2012, the Iranian MAHER CERT posted a note announcing the discovery of a new targeted attack dubbed “Flamer”. On Monday 28 May 2012 aat 9am EST, after an investigation prompted and supported by the International Telecommunication Union, Kaspersky Lab and CrySyS Lab from Hungary announced the discovery of Flame (aka Skywiper), a sophisticated cyber-espionage toolkit primarily targeting Windows computers in the Middle East.
Several hours later, around 4PM GMT, the Flame command-and-control infrastructure, which had been operating for years, went dark.
For the past weeks, Kaspersky Lab has been closely monitoring the C&C infrastructure of Flame. In collaboration with GoDaddy and OpenDNS, we succeeded in sinkholing most of the malicious domains used by Flame for C&C and gain a unique perspective into the operation.
Before going further, Kaspersky Lab would like to thank the “GoDaddy Network Abuse Department” and to William MacArthur for their fast reaction and exceptional support of this investigation. The OpenDNS security research team also offered invaluable assistance during the course of this investigation.
Our findings from analysing the infrastructure can be found below.
Since both Flame and Duqu appear to be targeting similar geographical regions and have been created with similar goals in mind, we will provide an analysis from the point of view of comparing the Flame C&C infrastructure with the Duqu infrastructure.
In the past, Kaspersky Lab analyzed the Duqu C&C infrastructure and found several important details, such as the attackers’ preference for CentOS, the use of SharpSSH to control the proxy servers and the huge number of hacked proxies used to hide the true identity of the attackers.
In the case of Flame, we performed a similar analysis. First of all, it’s interesting to point out a big difference from Duqu: while all the Duqu C&C proxies were CentOS Linux hosts, all of the known Flame C&C are running Ubuntu.
Additionally, while Duqu used the super stealthy way of hiding the true IP of the mothership using SSH port forwarding, Flame’s scripts are simply running on the respective servers. The reason is simple — on Monday May 28, all control scripts started returning 403/404 errors. In the case of Duqu, the real malware scripts were on a remote server and were never found.
From this point of view, we can state that the Duqu attackers were a lot more careful about hiding their activities compared to the Flame operators.
Here’s a comparison of the Duqu and Flame C&C infrastructure:
|Server OS||CentOS Linux||Ubuntu Linux|
|Control scripts||Running on remote server, shielded through SSH port forwarding||Running on servers|
|Number of victims per server||2-3||50+|
|Encryption of connections to server||SSL + proprietary AES-based encryption||SSL|
|Compression of connections||No||Yes, Zlib and modified PPMD|
|Number of known C&C’s domains||n/a||80+|
|Number of known C&C IPs||5||15+|
|Number of proxies used to hide identity||10+||Unknown|
|Time zone of C&C operator||GMT+2 / GMT+3||Unknown|
|Locations of servers||India, Vietnam, Belgium, UK, Netherlands, Switzerland, Korea, etc...||Germany, Netherlands, UK, Switzerland, Hong Kong, Turkey, etc...|
|Number of built-in C&C IPs/domain in malware||1||5, can update list|
|Servers status||Most likely hacked||Most likely bought|