A proxy botnet named ‘Socks5Systemz’ has quietly infected 10,000 computer systems worldwide, utilizing malware loaders such as ‘PrivateLoader’ and ‘Amadey’ to compromise these devices.
Socks5Systemz specializes in turning these infected systems into traffic-forwarding proxies, catering to the demands of subscribers willing to pay between $1 and $140 per day in cryptocurrency to access this proxy service. Although this botnet, detailed in a BitSight report, has been in operation since at least 2016, it managed to stay relatively under the radar until recent revelations.
BitSight’s analysis unveils that the Socks5Systemz botnet is distributed through malware like ‘PrivateLoader’ and ‘Amadey,’ often propagated through various means, including phishing, exploit kits, and trojanized executables downloaded from P2P networks. These malware samples, named ‘previewer.exe,’ inject the proxy bot into the host’s memory and ensure persistence via a Windows service named ‘ContentDWSvc.’ The bot’s payload is a 300 KB 32-bit DLL utilizing a domain generation algorithm (DGA) system to communicate with its command and control (C2) server, sharing profiling information about the compromised machines.
The C2 server can issue commands to the bot, including ‘idle,’ ‘connect,’ ‘disconnect,’ ‘updips,’ and ‘upduris,’ with ‘connect’ being a crucial command, enabling the bot to establish a backconnect server connection over port 1074/TCP. The infected devices are then offered as proxy servers, primarily used for illegal or malicious purposes.
BitSight’s research uncovers a control infrastructure consisting of 53 proxy bot, backconnect, DNS, and address acquisition servers primarily based in France and across Europe, with a noticeable global impact. Subscribers access Socks5Systemz services through ‘Cryptomus,’ an anonymous payment gateway, and choose between ‘Standard’ and ‘VIP’ subscription tiers.
These proxy botnets have a substantial impact on internet security and are frequently used for activities like shopping bots and bypassing geo-restrictions, making them a lucrative and concerning aspect of the cyber landscape.
