HardBit ransomware continues to evolve as a serious threat to organizations worldwide. The latest version, HardBit 4.0, emerged as an upgraded variant of a strain that has been active since 2022, bringing with it more advanced features and enhanced techniques to avoid detection.
This newest iteration represents a significant step forward in the ransomware’s ability to evade security measures while maintaining control over infected systems.
Unlike many competing ransomware groups, HardBit operators do not currently maintain a public data leak site for double extortion tactics, instead focusing solely on encryption-based ransom demands.
The attack chain begins with threat actors targeting vulnerable entry points in network infrastructure.
Picus Security analysts identified that HardBit 4.0 actors establish initial access through brute-force attacks against open Remote Desktop Protocol (RDP) and Server Message Block (SMB) services.
Once they gain entry to a system, attackers immediately focus on harvesting credentials to move laterally across the network and expand their foothold.
Picus Security researchers noted that the malware employs a multi-stage deployment strategy that makes detection particularly challenging.
The distribution method relies on Neshta, a file-infecting virus that has existed since 2003, which now serves as a dropper mechanism specifically designed to deliver and execute HardBit 4.0.
This approach bypasses traditional antivirus detection because Neshta modifies executable files and establishes persistence through registry manipulation.
The Neshta dropper operates through a four-step process that demonstrates technical sophistication. When executed, it first reads its own binary file and extracts the HardBit payload from specific memory offsets.
Lateral Movement
The dropper then decrypts the HardBit header and body, writes the reconstructed ransomware binary to the system temporary directory, and finally launches the malware through legitimate Windows execution functions.
To ensure the malware persists across reboots, Neshta copies itself to the system root directory as a hidden file and modifies registry keys so that whenever a user attempts to run any executable file, the malware automatically executes first.
Beyond persistent access, HardBit 4.0 implements aggressive defense evasion tactics that target security software directly.
The malware modifies multiple Windows Registry entries to disable critical Windows Defender features including Real-Time Monitoring, Tamper Protection, and Anti-Spyware capabilities.
Additionally, the binary is obfuscated using a modified version of ConfuserEx protector, making reverse engineering and analysis difficult for security professionals.
A unique feature that sets HardBit 4.0 apart involves a passphrase protection mechanism that requires attackers to provide specific authorization keys at runtime, preventing accidental or automated sandbox detonation that could expose the malware’s behavior to security researchers.
Organizations can enhance their defenses against HardBit 4.0 by monitoring for suspicious RDP and SMB activity, implementing strong credential management practices, and maintaining updated backup systems isolated from network access to ensure recovery options remain unavailable to attackers.
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