Russian underground cyber-markets are known venues for purchasing high-quality hacking tools and services. Many such tools, popular worldwide, make their first appearances on closed Russian forums. There are two main types of sellers on these platforms: well-known members with seniority and strong reputations, who have already sold tools and received positive buyer feedback, and an emerging “shell profile” type of user. According to our recent analysis, such users typically register to a forum a few days before posting an advertisement for the tool. These new users often enlist the aid of forum administrators and more senior members, by providing them with a copy of the tool for their review, and thus gain the trust of potential buyers.
For example, CTB-Locker, a malware program, was first advertised on a Russian underground forum on June 10, 2014 by a user called Tapkin. This ransomware scans the computer for data files, encrypts them with a unique algorithm, and demands a ransom to release them. Tapkin registered on this forum on June 2, 2014, several days before posting the advertisement, and posted a total of five messages to the forum, all on the subject of CTB-Locker. Around this time, a user by the same name posted identical information on other forums.
Tapkin registered to another Russian underground forum on June 13, 2014, and three days later, he advertised the tool on the forum. This was the first and only thread that Tapkin started on this platform, and all of his posts were about this topic.
Tapkin stopped selling CTB-Locker on June 27, but on November 19, 2014, he posted another advertisement, this time for “serious” clients only. Tapkin last advertised the ransomware on a carding forum on December 8, 2014, after registering to this forum the same day.
Thus, in three cases, Tapkin registered to a forum a few days before posting an advertisement for the tool and did not participate in any other forum discussions. As a newly created profile, Tapkin lacked seniority and therefore had low credibility. However, our impression is that this user demonstrates knowledge regarding the tool, its capabilities and can answer questions regarding the technical component of the tool fluently. An analysis of Tapkin’s posts indicates that behind the shell profile is not one person, but rather a group of people who developed the tool together.
This username appears to have been created for the sole purpose of selling the ransomware, which was only advertised on Russian-speaking platforms. On May 19, 2015, a well-known forum user posted a message stating that his computer had been infected by CTB-Locker and asking for Tapkin. However, Tapkin had by then already disappeared.
Another example of malware advertised by a new forum member is the Loki Bot password and coin wallet stealer. Loki Bot, written in C++, can steal passwords from browsers, FTP/SSH applications, email accounts, and poker clients. It has an option to configure C&C IP addresses or domains.
This bot, which works on Windows versions XP, Vista, 7, 8, and 8.1, is relatively new and is still under development. It was first advertised on a well-known Russian underground forum in early May 2015 by a new user with no reputation. A week later, a user by the same name registered on two other well-known underground forums attempted to boost his credibility by sending the forum administrator a test version of the malware. Similar to the previous example, we assume that a group of people is behind this user as well.
We can see that new users are registering on Russian underground forums for one purpose only, to sell a particular malware program, and their entire online presence is focused on this. They register to a forum a few days before posting an advertisement for the tool and do not participate in other forum discussions. Newly created profiles lack seniority and therefore have low credibility ratings. Sometimes such users attempt to improve their credibility by sending the forum administrator a test version of the malware. In some cases we can see that behind the shell profile there is a team, and not an individual. They appear suddenly and disappear just as suddenly after their business is completed.