A technical report on sKyWIper was released by the Laboratory of Cryptography and Systems Security (CrySys Lab) over at the Budapest University of Technology and Economics yesterday covering their analysis of the malware – discovered earlier in May 2012 – and they also drew the conclusion that this threat is related (if not identical) to the malware described by the Iran National CERT (MAHER) – referred to as Flamer. Meanwhile, Kaspersky released some of their own analysis of “Flame” on Monday and created a FAQ based upon their interpretation of the malware’s functionality and motivations.
While it’s practically a certainty that the malware was created and infected a number of victims before it was “detected” in May, I’d caution against some of the jumps people are making related to the attribution of the threat.
Firstly, this behemoth of a malware pack is constructed of a lot of different files – many of which are not malicious; with the package including common library files (such as those necessary for handling compression and video capture) as well as the Lua virtual machine. Secondly, when you’re limited to an 8.3 file naming convention, even malicious files are likely to have name collisions – resulting in many spurious associations with past, unrelated, threats if you’re googling for relationships. And finally, why build everything from scratch? – it’s not like malware authors feel honor bound to adhere to copyright restrictions or steal code from other malware authors – nowadays we see an awful lot of code recycling and simple theft as criminals hijack the best features from one another.
As you’d expect from a bloated malware package developed by even a marginally capable hacker, there are a lot of useful features included within. It’s rare to see so many features inside a single malware sample (or family), but not exceptional. As Vitaly Kamluk of Kaspersky stated – “Once a system is infected, Flame begins a complex set of operations, including sniffing the network traffic, taking screenshots, recording audio conversations, intercepting the keyboard, and so on,” – which is more typical of an attack kit rather than a piece of malware. What do I mean by “attack kit”? Basically a collection of favorite tools and scripts used by hackers to navigate a compromised host or network. In the commercial pentesting game, the consultant will normally have a compressed file (i.e. the “attack kit”) that he can shuttle across the network and drop on any hosts he gains access to. That file contains all of the tools they’re going to need to unravel the security of the (newly) compromised host and harvest the additional information they’ll need to navigate onto the next targeted device. It’s not rocket science, but it works just fine.
I’m sure some people will be asking whether the malware does anything unique. From what I can tell (without having performed an exhaustive blow-by-blow analysis of the 20Mb malware file), the collection of files doesn’t point to anything not already seen in most common banking Trojans or everyday hacking tools. That doesn’t make it less dangerous – it merely reflects the state of malware development, where “advanced” features are standard components and can be incorporated through check-box-like selection options at compile time.
For malware of this ilk, automated propagation of infections (and infectious material) is important. Flame includes a number of them – including the commonly encountered USB-based autorun and .lnk vulnerabilities observed in malware families like Stuxnet (and just about every other piece of malware since the disclosure of the successful .lnk infection vector), and that odd print spooler vulnerability – which helps date the malware packaged. By that I mean it helps date the samples that have been recovered – as there is currently no evidence of what the malware package employed prior to these recent disclosures, or what other variants that are circulating in the wild (and not been detected by antivirus products today).
Are these exploits being used for propagation evidence that Stuxnet, Duku and Flame were created and operated by the same organization? Honestly, there’s nothing particularly tangible here to reach that conclusion. Like I said before, criminals are only too happy to steal and recycle others code – and this is incredibly common when it comes to the use of exploits. More importantly, these kinds of exploits are incorporated as updates into distributable libraries, which are then consumed by malware and penetration tool kits alike. Attack kits similar to Flame are constantly being updated with new and better tool components – which is why it will be difficult to draw out a timeline for the specific phases of the threat.
That all said, if the malware isn’t so special – and it’s a hodgepodge of various public (known) malicious components – why has it eluded antivirus products in the victim regions for so long? It would be simple to argue that these regions aren’t known for employing cutting-edge antimalware defenses and aren’t well served with local-language versions of the most capable desktop antivirus suites, but I think the answer is a little simpler than that – the actors behind this threat have successfully managed their targets and victims – keeping a low profile and not going for the masses or complex setups.
This management aspect is clearly reflected in the kill module of the malware package. For example, there seems to be a module named “browse32″ that’s designed to search for all evidence of compromise (e.g. malware components, screenshots, stolen data, breadcrumbs, etc.) and carefully remove them. While many malware families employ a cleanup capability to hide the initial infection, few include the capability of removing all evidence on the host (beyond trashing the entire computer). This, to my mind, is more reflective of a tool set designed for human interactive control – i.e. for targeted attacks.
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