A group of malware researchers has discovered a new strain of Mac malware undetected my most security firm, but more intriguing is the speculation that the malicious code may have been developed by the Italian security firm HackingTeam.
Pedro Vilaça, a security researcher at SentinelOne, has published an interesting post titled “The Italian morons are back! What are they up to this time?” that analyzes a sample of OS X RCS recently received by the expert. Remote Control System, aka RCS, is the surveillance software developed by the Italian firm and used by a large number of government and intelligence agencies worldwide.
The sample was uploaded on February 4 to the VirusTotal which at the time confirmed that the malware wasn’t detected, meanwhile at the time I’was writing it has a detection rate of 15/55.
The analysis of the new sample received by Vilaça revealed that the installer was last updated in October or November, and the configuration date for this sample is October 2015, a few months after the HackingTeam hack.
“First we locate the configuration file encryption key and then decrypt it. There we can find the configuration dates for this sample, 2015-10-16, confirming that this is indeed a post hack sample. The C&C server IP for this sample is 220.127.116.11. It’s already down and I didn’t verified if it was up before starting to tweet about this sample on last Friday” states Vilaça.
Still,Vilaça used the Shodan search engine and VirusTotal to perform further researches on the C&C server, he discovered that the machine referenced by this OS X RCS sample was still active in January.
What happened to HackingTeam after the clamorous data breach? At the time they promised to release a new version that they were telling was not affected by the hack. Is this really true?
The company announced to release a new version of its surveillance software, but the analysis of the source code of this new sample suggests that is has been compiled out of the leaked source code base, and apparently it hasn’t introduced new improvements.
“I can guarantee you that this sample code is coming from that code base, up to the last commit (there are probably newer commits after the leak). HackingTeam appears to have resumed their operations but they are still using their old source code for this. Of course there is a question of are they using both old and the new promised source code or were they just lying about it and resumed operations with old code since they are probably on a shortage of engineering “talent”? This is definitely a question their customers will have to ask them ;-).” continues the expert.
The expert concluded that the new strain of Mac malware is a very fresh sample that demonstrates that the HackingTeam is still alive and that is is operating under cover.
“HackingTeam is still alive and kicking but they are still the same crap morons as the e-mail leaks have show us,” Vilaça wrote. “If you are new to OS X malware reverse engineering, it’s a nice sample to practice with. I got my main questions answered so for me there’s nothing else interesting about this. After the leak I totally forgot about these guys :-).”
Another interesting analysis of this new sample of the RCS spyware has been published by Patrick Wardle, a cyber security expert at Synack. Wardle explained that the new sample is based on the old HackingTeam RCS code, but implements sophisticated techniques to evade detection and analysis.
Last summer, at Blackhat Wardle gave a presentation entitled Writing Bad @$$ Malware for OS X that provided suggestions as to how OS X malware could be improved, including the use of Apple’s native encryption scheme to protect malicious binaries.
“Diving in, the first thing we notice is that it is encrypted with Apple’s native OS X encryption scheme.” wrote Wardle. “… it’s nice to finally see some OS X malware that uses Apple’s native OS X encryption scheme, as well as custom packers. “
The expert noticed that the installer was “packed” with this technique to make hard reverse engineering and analysis.
At this point, there are two hypotheses on the origin of the sample:
Let me close with the last update provided by Vilaça in his analysis.
“I just found some unique code in this dropper. This code checks for newer OS X versions and does not exist in the leaked source code. Either someone is maintaining and updating HackingTeam code (why the hell would someone do that!?!?!) or this is indeed a legit sample compiled by HackingTeam themselves. Reusage and repurpose of malware source code happens (Zeus for example) but my gut feeling and indicators seem to not point in that direction.”
(Security Affairs – Hacking Team, OS X RCS)