The malware in question is the Sykipot Trojan, which has been found abusing various zero-day vulnerabilities in the past.
According to the researchers, the attackers misuse the flaw to make the target computer download the malware, which then searches for outlook, iexplore or firefox in the list of running processes. Once it has found them, it injects DLL files into them.
After that, the malicious binary creates a PDF file that apparently contains “CONUS rates” for traveling expenses in the continental US (click on the screenshot to enlarge it):
"The injected DLL will contact XXXhksrv.hostdefence.net/asp/kys_allow_get.asp?name=getkys.kys to download an encrypted configuration file," explain the researchers. "This file contains several commands that the victim will execute on the sending the results back to the C&C server."
The hostdefence.net domain on which the C&C server is hosted is located in China.
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