28 Dec Hashcat's GPU-accelerated Gauss encryption cracker GReAT
20 Nov New 64-bit Linux Rootkit Doing iFrame Injections Marta Janus
19 Apr OS X Mass Exploitation - Why Now? Kurt Baumgartner
22 Oct Java Malware Reconsidered, or, Java Brews a Fresh Bot of Malware Kurt Baumgartner
05 Aug Blackhat USA 2011 Talks Kurt Baumgartner
14 Jun Patch Tuesday June 2011 Kurt Baumgartner
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Previously, we’ve published a blogpost about the encrypted payload hoping that the crypto community will take on the challenge and break the encryption scheme to reveal the true purpose of the mysterious malware.
A few days ago, an interesting piece of Linux malware came up on the Full Disclosure mailing-list. It's an outstanding sample, not only because it targets 64-bit Linux platforms and uses advanced techniques to hide itself, but primarily because of the unusual functionality of infecting the websites hosted on attacked HTTP server - and therefore working as a part of drive-by download scenario.
Market share! It’s an easy answer, but not the only one.
In 2011, Apple was estimated to account for over 5% of worldwide desktop/laptop market share. This barrier was a significant one to break - Linux maintains under 2% market share and Google ChromeOS even less. This 15 year peak coincided with the first exploration by the aggressive FakeAv/Rogueware market targeting Apple computers, which we discovered and posted in April 2011 and later in May 2011, which no longer seem to be such an odd coincidence. Also, the delay in Apple malware until now most likely was not because Apple exploits were unavailable, or because the Mac OS X system is especially hardened. The 2007 "Month of Apple Bugs" demonstrated that the Mac OS X and supporting code is full of exploitable flaws. Safari, Quicktime, and other software on Apple devices is regularly exploited during pwnage contests, but widespread cybercrime attention hadn’t caught on until this past year.
At this point, we still don't know who is behind Flashfake, so we don’t know for sure that they were the same Mac OS X FakeAv/Rogueware group. Speculating that eastern euro-cybercrime is behind the botnet would be a pretty confident way to go right now. There are known groups from the region that have succeeded at wringing ad revenues from traffic hijacking. We don't believe that other sensitive data has been targeted. And the exploit distribution URLs that we are aware of have only targeted mac users. These factors limit the operational and technical needs of a financially motivated cybercrime gang.
In a sense, it would appear that their activity was somewhat similar to the Koobface or Tdss gangs. They haven't commited large unique financial crimes to attract the attention of law enforcement, and their malware contains hooks and other code to perform more sophisticated banking crime than search traffic hijacking, but they most likely were looking to make a multitude of small financial gains. On the other hand, thankfully, Apple hasn't given these guys ample notice to make their run. There can be plenty of money in that business - it is estimated that the Koobface guys ran off with millions after Facebook "outted" their operation under investigation. But based on the domain registrations we have examined, the individuals are not quite so public and they are hiding their identities while they hijack search engine traffic. The malware itself injects a number of hooks into running applications, much like the Zeus, SpyEye, and other spyware. If these were used for financial crimes, the group operating this botnet would need to organize money mules and accomplices to launder their stolen money, which would grow the group and attract the attention of other authorities.
On the technology side, Java is a big part of the puzzle. Although the Trojan is called Flashfake because users were being convinced to install the malware as an Adobe Flash update, more recent versions of the malware were being installed via client-side Java exploitation.
Three vulnerabilities were targeted with client-side exploits, none of them were 0day, which seem to have become much more difficult to come by. Besides, this set worked just as well for these operators. It is interesting to note the duration of time from the original Oracle Java security update to the Apple Java security update, and when in that timeframe the release offensive security research publicly appeared. And, when were Metasploit open source exploit modules were released targeting the related Java vulnerabilities? The windows of time may be alarming – these are not 0day exploits, but Apple simply hasn’t released patches, leaving their customers exposed to the equivalent of known 0day exploits.
2012-02-15 Oracle patches Atomic Reference Array vulnerability
2012-03-10 First Itw exploits targeting the vuln
2012-03-30 Metasploit developers add Java atomicreferencearray exploit module
2012-04-03 Apple patches their code
2011-05-12 Reported to vendor
2011-11-18 Oracle patched their Java SE
2011-11-30 Metasploit developers add "Rhino exploit" module
2011-11-30 Krebs reports operational Blackhole site with the new Java exploit
2012-3-29 Patched by Apple
"Deserializing Calendar objects"
2008-08-01 Reported to Sun with first instance of the vulnerability
2008-12-03 Sun patches their code (Sun link down)
2009-05-15 Apple patches MacOSX code
2009-06-16 Metasploit developers add Java deserialization exploit
Also on this list is a lame exploit described as a signed applet social engineering trick.
I'd prefer to call it the "the terribly confused user presented with the Java 'do you want to trust this applet?' dialog and will run anything you present them" gamble. It first became a part of the Metasploit exploit module list on 2010-01-27. Basically, these guys present the user with a file that the user thinks is a JavaUpdate provided by Apple Inc themselves, which they grant trust to perform any action on their machine. The downloader will then communicate with a couple of sites to register and download new Flashfake components. These components in turn, collect the system UUID and timestamp, then auto-generate with a crypto algorithm a set of C2 domains, along with maintaining a list of hard coded domains. A couple of the newer components inject into running processes on the system hooking software functionality and hijacking traffic, much like past TDS malware.
At Virus Bulletin 2011, we presented on the exploding level of delivered Java exploits this year with "Firing the roast - Java is heating up again". We examined CVE-2010-0840 exploitation in detail, along with variants of its most common implementation on the web and some tools and tips for analysis. Microsoft’s security team presented findings for 2011 that mirrored ours in relation to Java exploit prevalence on the web – it is #1! At the same time, aside from the recent, well-known BEAST Java implementation, it is striking that it has been very uncommon to see Java backdoors, Trojans and spyware. But that lack of Java malware variety is beginning to change. My colleague, malware analyst Roman Unucheck, identified a new Java bot with some interesting characteristics that we named "Backdoor.Java.Racac".
Blackhat USA 2011 wraps up and the Defcon conference starts today. There is a little something for everyone in security here. Aside from the contests, networking, meeting folks in the industry and putting faces to names, I thought that the briefings had two fantastic talks.
The first of the two focused on breaking out of the official virtualization platform for Ubuntu and Red Hat, Kernel Based Virtual Machine, or KVM. The second focused on the massive challenges that exist in the current SSL infrastructure, or PKI.
KVM is gaining traction in the virtualization and cloud space, but there hasn't been public security research efforts on this platform like there has been with VMWare and Xen. Nelson Elhage pointed out that the adoption of the platform will bring with it increased scrutiny, and that parts of the existing code is a "gold mine" for vulnerability hunters. He methodically reviewed CVE-2011-1751, and delivered the goods with an exploit demo implementing not ROP to evade DEP, but an in-memory timing chain fragment reuse technique. While the cloud has been under attack with multiple known exploits for Xen and VMWare from Invisible Things Lab and Immunity, Elhage pointed out that virtualization does not provide a reliable layer of security through isolation on its own.
Probably the best speaker at the conference this year was Moxie Marlinspike. His presentation was a talk about trust, and the massive breakdown of trust related to SSL this past year. He reviewed the ridiculous antics around the certificate authority Comodo hack, how cemented these organizations are in the infrastructure in the face of the repeated intrusions and mistaken certificate issuance, and what is missing from the infrastructure. To help overcome these challenges, he proposed adding "trust agility" to the infrastructure. He meant two enhancements need to be added to the trust model:
He reviewed why DNSSEC would continue to centralize trust in its model, and proposed a new implementation of certificate handling used in encrypted communications with web servers, where software clients contact "Notaries" for certificates to maintain encrypted communications, instead of letting web sites contact CAs to validate them. All of these ideas and the implementation of the concepts are available as a part of his Convergence project website. Details are provided there and Firefox users can download a plugin there.
This month's patch Tuesday is a sizable one by any standards, following the quiet Tuesday that my colleague Roel Schouwenberg described last month. Microsoft is patching a total of 34 vulnerabilities in 16 bulletins, MS11-038 through MS11-051. At least eight different Microsoft product lines are updated, and Adobe is coordinating release of Reader, Acrobat, Shockwave and Flash updates as well today.
So we are looking at patching the following programs:
Microsoft Windows, Microsoft Office, Internet Explorer, .NET, SQL, Visual Studio, Silverlight, ISA and Adobe Reader, Acrobat, Shockwave and Flash player. More than half of the vulnerabilities being patched exist in the Internet Explorer and Microsoft Excel software components, frequent targets of drive-by and spear phishing attacks.
Most interesting is MS11-050, a single patch that knocks out 11 separate Internet Explorer vulnerabilities, some enabling information disclosure (cookiejacking), memory corruption and remote code execution: CVE-2011-1250, CVE-2011-1251, CVE-2011-1252, CVE-2011-1254, CVE-2011-1255, CVE-2011-1256, CVE-2011-1260, CVE-2011-1261, CVE-2011-1262. The additional VML patch MS11-052 knocks out another Internet Explorer vulnerability, CVE-2011-1266.
Microsoft already pointed out that the Internet Explorer patch addressing "cookiejacking" is not a particularly high risk issue because it is relatively unknown to them as an attack vector, and because there are more substantial social engineering techniques. While those points may be true, now that the techniques are more widely discussed, the risk of them being abused by more attackers goes up as well.
Eight different privately reported vulnerabilities are being patched in Microsoft Excel alone by MS11-045, each of which allow for remote code execution. We are still reviewing why the patch is rated "important" and not critical for the various Excel versions.
The patches that stand out result in remote code execution within Internet Explorer, Office and Silverlight. The recent history of attacks on consumer and corporate users, including the many successful spear phishing and APT attacks should help increase the urgency of these patches.
On the server side in the cloud, Microsoft is patching a vulnerability that could be abused in a DoS attack that could only be staged from within the cloud. MS11-047 is rated an "Important" patch for Windows 2008 versions, correcting a flaw in Hyper-V where a guest could send a malformed packet to the VMBus and result in denial of service on the server. MS11-039 is the Silverlight patch that could not only be used in a remote code execution attack on the client side, but also can be used to remotely run arbitrary code on vulnerable IIS web servers.
At least eight of the nine patches rated "Critical" requires a restart, be prepared for this interruption. We recommend applying all of this month's released patches asap.
Security researchers from around the world are digesting the weekend's fare at Infiltrate2011, organized by security outfit Immunity. "No policy or high-level presentations, just hardcore thought-provoking technical meat" was promised, and presenters served it up sizzling.The sessions folded in a variety of topics slicing up current offensive security issues with some defensive interest mixed in. Discussions spread from technical wizardry attacking hardened linux kernels to general network exploration and reconnaisance. Infiltrate2011 itself follows somewhat on the Blackhat/Defcon conference model, but reduces the corporate marketing at those conferences. The peer reviewed set of presentations and research sponsored by one of the best known offensive security/penetration testing groups in the business sets the bar high and undistracted for the level of technical content. The final agenda is listed here.
In this Q&A session with Ryan Naraine, Kaspersky Lab malware researcher David Jacoby dispels the myth surrounding Linux as a malware-free platform and makes the case that misconfigurations and other security problems on Linux contributes to the malware epidemic on Microsoft's Windows operating system.
Working on an efficient generic shellcode detection engine and verifying results with randomly generated input, I've effectively ended up fuzzing different open source disassembler libraries. The disassembler library of choice for my current project is libdasm because of its comparatively long history and public domain license. But writing a sound and complete x86 disassembler is obviously not a trivial task due to the complex nature of the x86 instruction set.
libdasm used to have issues correctly disassembling certain floating point instructions in the past, but this was simply caused by an off-by-three error in the opcode lookup tables (three NULL rows missing) and thus the fix was comparatively easy.
On Saturday "Linuxtag 2006" closed in Wiesbaden (Germany). According to the organisers, it’s Europe's biggest Linux Expo.
At the Kaspersky stand we talked to a lot of visitors. Pretty soon, it dawned on us exactly what the biggest threat to Linux systems is: the almost overwhelming belief in the invulnerability of Linux.
Nearly every visitor accepts the need to protect Windows against malicious code (although even at a Linux fair you find people believing that a firewall is all you need to keep viruses and worms away). But many people we spoke to were unable to think of Linux as potentially vulnerable; after all, they argued, a Linux user would never go online with root rights as typical Windows XP home users do.
But such thinking overlooks some important facts:
- You don’t need to have root privileges to delete a user’s home directory of a user or access his personal data - you only need to run malicious code with user privileges. (And not every user makes daily backups which could mitigate the potential damage.)
- The number of new malicious programs for an operating system isn’t related to the number of known security flaws, but to the number of installations. In Germany, the number of Linux distributions installed is growing rapidly, and overall, the number of malicious programs for Linux more than doubled between 2004 and 2005).
- To access a system, a virus writer doesn’t need 300 vulnerabilities - one is enough.
- Vulnerabilities exist prior to their being identified by the developers who report them. Virus writers actively search for vulnerabilities, but keep their discoveries to themselves.
- Only a perfect system can offer perfect security. In his "Areas for Improvement in the 2.6 Kernel Development Process" Andrew Morton (lead maintainer of the Linux production kernel) pointed out that the number of new bugs in the current 2.6 kernel are causing concern, and might lead to the development process being halted until existing problems are fixed.
Just to avoid any misunderstanding: of course Linux is currently more secure than the average Windows installation. This is due to things like user/root separation, a smaller number of installations, and rapid reaction to reported vulnerabilities. And currently, given the relatively small number of malicious programs for Linux, installing a virus scanner is more a gesture of friendship towards the Windows users you share files with. But taking all of this, and coming to the conclusion that your own system is practically invulnerable will make it easy for malware to spread on Linux systems in the future.
Let's take a look at what history teaches: In 2000, the VBS.Loveletter worm took just a few hours to spread across unsecured Windows computers around the world. So far, nothing on this scale has hit the Linux world. But the question is: when the day comes, will users and companies have enough time to choose and install a reliable virus scanner before their systems are hit?