What can hackers do to a server once they’ve broken into it? A lot. Some install malware and make it part of a botnet. Others steal valuable data stored within. Still others, like those mentioned in this post, sell login credentials at shady marketplaces in the Dark Web.
Thousands of servers for sale
Earlier this month, researchers at Kaspersky revealed yet another alarming discovery in the field of cybercrime. Login credentials to over 70,000 hacked servers were being sold at an online marketplace known as xDedic. Like many underground online marketplaces where tech-savvy crooks trade illicit goods, xDedic can only be reached through the Dark Web.
Apparently, hacked servers are very affordable. Prices for hacked servers were found to go as low as 6 USD. Most of the servers were located in Brazil, China, Russia, India, Spain, Italy, France, Australia, Republic of South Africa, and Malaysia.
Launched in 2014, xDedic gained its reputation as a leading source of compromised server login credentials when 3,000 servers were added to its inventory sometime in 2015. Business has boomed since then.
Tools of the trade
xDedic not only provides a platform for buying and selling hacked servers. It also offers both buyers and sellers tools they can use in finding servers that suit their specific objectives as well as carrying out remote administration via RDP.
One example is a tool used by sellers to scan a hacked system and obtain relevant information such as the Windows version, size of RAM, type of CPU, whether ports 25 and 80 are open, type of VM used, antivirus installed, upload/download speeds, and so on. The same profiling tool is used to search for an RDP service on the server and then to patch it if any is found.
The patch modifies the RDP settings to allow multiple user logins, which would enable a buyer to access the server without alarming the server’s legitimate administrator. The buyer could then access the hacked server through xDedic’s own RDP client.
What can buyers do with a hacked server?
A hacked server can open up a lot of opportunities to a buyer, especially one who operates in the cybercrime industry. Because most of these servers have not yet been blacklisted by blacklisting engines and web reputation sites, they’re perfect for a variety of cyber attacks, including ransomware, malvertising, DDoS, phishing, and many others.
Of course, if a server also happens to store or provides access to storage systems that contain sensitive data, a buyer who specializes in identity theft could have a field day.
The Kaspersky researchers observed a marked interest for servers containing accounting, tax reporting and point-of-sale (POS) applications. Apparently, buyers need these applications for carrying out fraudulent operations. By making use of existing software, attackers can avoid arousing attention.
What countermeasures can help?
Servers that end up at xDedic acquire certain characteristics that can help cybersecurity specialists determine whether a server has been hacked. For instance, the profiling tool mentioned earlier, which is installed on a hacked server after the server is compromised (usually through brute-force attacks), communicates with certain Command-and-Control locations.
In addition, it has been found that the hacked servers are also infected with other pieces of software, including a certain Trojan, bitcoin mining software, and a wrapper for a proxy tool, among perhaps others. For more details about xDedic and these malicious tools, refer to the Kaspersky report on the subject.
Of course, prevention is always preferable to treatment. Once you’ve determined that your servers are safe, you should carry out server hardening to prevent future compromises.