'Time Bomb' Attack Out Of China Defused

Mandiant's in-depth report published last month on a prolific cyberespionage team tied to the Chinese military was, in turn, used as a lure in other targeted attacks -- by what appears to be different Chinese hacker groups.

The attacks, spotted by Seculert, used a phony version of the report as a lure in a spearphishing attack against Japanese and Chinese journalists. The targeted attack against the Japanese victims came with an interesting twist: a "time bomb" element, according to Aviv Raff, CTO at Seculert.

Mandiant's report calls out the People's Liberation Army Unit 61398 as the APT1 group responsible for cyberspying against multiple industries.

The malware used in the attacks on Japanese journalists was programmed to trigger during 8 a.m. and 7 p.m. only, according to Raff. Raff says aside from the malware communicating with legitimate Japanese websites, it also came with another command-and-control domain in memory, one that was registered to a free dynamic DNS server and went to a Korea-based IP address.

During the programmed time frame, the malware would communicate with "the real C2 server," he says, rather than the legit Japanese websites. It also would then download additional malware.

"We currently don't know why they chose specifically this time frame. However, the long time span can suggest the attackers might be targeting more than just the Japanese," Raff says.

The good news is that the domain was shut down on Monday by the dynamic DNS service provider -- just in time because the time bomb was supposed to be triggered on Tuesday. "That's good because the 'time bomb' was not triggered," Raff says. "It was supposed to download additional malware in the next stage of the attack."

But the downside is that since the domain was suspended, Raff and his team were unable to get a look at that second stage malware in the attack to examine what it was up to. "But looking at past similar attacks, it can vary from information stealing, to a wiper module, like in Flame or Shamoon," he says.

The full post from Seculert, including screen shots, is here.

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