The BKA/Ransom Trojan comes now with child pornography (updated)

The so called “BKA Trojan” (BKA stands for German Federal Criminal Police) malware which is also known as the Ransom trojan in other countries, has found a more convincing way to fool computer users to pay. Now, together with other eight possible misdeeds,  the user is accused of hosting and distributing child pornography materials from his computer. The computer is identified via IP address and geo-ip location (see top right corner).

 

Same as the other variants known, the malware locks the user’s computer and asks 100€ (135 USD) to be paid via UKash or paysafe in order to unlock the computer, not destroy the data on it and not be condemned and punished. The cybercriminals are constantly trying new texts in order to look as convincing as possible.

The malware is distributed via drive by downloads as an executable file with temporary names. Once executed, a file having various names and the size of around 53KB is being used.

A brief analysis of the malware shows that immediately after execution it sets various registry keys so that the computer doesn’t start anymore in the normal way. In this mode  the user is forced to pay the ransom. Our tests have shown that with this variant, even booting in Safe mode and Safe Mode with confirmation will cause a blue screen (BSOD). This means that the only way to remove the malware is to boot the computer via a Rescue System and perform a full system scan and cleanup.

All Avira products detect the malicious files as  TR/Winlock.JQ and TR/Ransom.EB.

 

Update:

Starting with the engine version 8.2.10.246  all variants of the trojan are detected with a generic detection as TR/Dropper.VB.Gen.

 

Sorin Mustaca

IT Security Expert

Alexander Vukcevic

VLAB Manager, Germany