The malware BKDR_ADDNEW, better known as 'DaRK DDoSseR' in the underground, is a tool that provides distributed denial of service (DDoS) capability combined with password stealing functionality. The tool costs $30 and has been available for several years.
Recently, our friends at FireEye reported seeing computers that had been compromised by BKDR_ADDNEW and later updated with Gh0st RAT. While Gh0st RAT has been used in many targeted attacks, this threat and its many variants (PDF), are widely available to both APT actors and cybercriminals alike.
When executed, BKDR_ADDNEW connects to a TCP port (the ports used by the samples analyzed were 443, 3176 and 3085 but the default port is 3175) to receive remote commands from a malicious operator. Some of the available commands include downloading of files, stealing Mozilla Firefox passwords, showing DNS, and sending application privileges among others. It also has the capability to launch denial of service (DOS) attacks.
Based on our investigation, BKDR_ADDNEW has built-in functionality that allows malicious actors to “update” the malware on a compromised computer.
Using this functionality it would be simple for the operators of a DaRK DDoSseR botnet to instruct the compromised systems under their control to download and execute Gh0st RAT.
Why would both types of malware be present on a compromised computer? There are a number of alternative explanations:
- The owners of a DaRK DDoSseR-based botnet have sold “installs” to other cybercriminals. There is a thriving underground market for already compromised computers and this could be a case or change of ownership.
- While DaRK DDoSseR has denial of service capability and the ability to steal passwords it is not a fully featured RAT (remote access tool) that is capable of file browsing, taking screen screenshots, and turning on a microphone or webcam. Perhaps the operators of this botnet wanted some additional functionality so they instructed the already compromised hosts to download and install Gh0st RAT.
You may also consult our earlier blog posts that have discussed other RATs such as JACKSBOT, PlugX, and Poison Ivy:
Trend Micro protects users from this threat via the Smart Protection Network that detects the said malware.