Telegram-Controlled TgRat Trojan Targets Linux Servers

Summary: The TgRat Trojan, initially targeting Windows, has evolved to infect Linux systems and operates through the messaging app Telegram, allowing cybercriminals to control infected machines remotely. This sophisticated Remote Access Trojan (RAT) utilizes Telegram’s infrastructure to execute commands and exfiltrate data, making detection challenging for cybersecurity teams.

Threat Actor: Cybercriminals | cybercriminals
Victim: Linux systems | Linux systems

Key Point :

  • TgRat connects to a Telegram bot for command and control, leveraging the platform’s popularity in corporate environments.
  • The trojan self-terminates if it detects it is not running on a targeted machine, enhancing its stealth.
  • It can perform various malicious actions, including downloading files, taking screenshots, and executing scripts remotely.
  • Detection can be achieved by monitoring unusual network traffic to Telegram servers from local devices.

Meet TgRat Trojan: Once known for targeting Windows devices, the new version targets Linux and runs its command and control center through the popular messaging app Telegram.

Cybersecurity experts at Dr. Web have found a sophisticated Linux-based Remote Access Trojan (RAT) called TgRat, which uses a clever disguise: it’s controlled through a private Telegram chat.

This malware, which allows cybercriminals to remotely control infected machines, exfiltrate data, and execute commands, was initially discovered in a Windows version two years ago but has now been adapted to target Linux environments.

The TgRat trojan operates by connecting to a Telegram bot, a method that takes advantage of the popular messaging platform’s widespread use in corporate settings. This unique control mechanism enables attackers to issue commands to the infected system secretly, making it difficult for victims to detect the infection.

Upon infection, TgRat checks to confirm it is running on a targeted machine by comparing the computer’s name hash against an embedded string. If the values do not align, the malware self-terminates, avoiding detection. If it does match, the trojan connects to the Telegram bot and awaits further instructions from its operators.

Telegram-Controlled TgRat Trojan Targets Linux Servers
The screenshot shows remote interaction with a Linux system using command execution to create a file, write to it, and read its contents, confirming successful command execution and output retrieval (Screenshot: Dr. Web)

Once established, TgRat can execute various malicious activities, including downloading files, taking screenshots, and running commands remotely. Its design allows for the execution of entire scripts through a single message, enhancing its effectiveness and stealth.

According to Dr. Web’s blog post, the discovery came after a hosting provider reported suspicious activity, prompting Doctor Web’s virus lab to investigate. They found a trojan dropper that installed the TgRat malware on the server, leading to further analysis of its capabilities.

Experts warn that the use of Telegram for command and control makes this trojan particularly stealthy. The regular traffic to Telegram’s servers can easily disguise malicious communications, complicating detection efforts for network security teams.

While the TgRat trojan is a sophisticated threat, cybersecurity professionals can identify its activity by monitoring network traffic. Unusual exchanges with Telegram servers from local network devices can signal a potential compromise, allowing for timely intervention.

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Source: https://hackread.com/telegram-controlled-tgrat-trojan-targets-linux-servers