Infostealer's Stealth: 0/64 AVs Miss Hidden Payload

In the ever-evolving landscape of cyber threats, adversaries continuously refine their tactics to bypass traditional security measures. A recent analysis brought to light a particularly concerning multi-stage infostealer, initially disguised as a benign “game cheat.” What makes this case especially noteworthy is the payload's astonishing ability to evade detection, with zero out of 64 antivirus engines flagging it on VirusTotal.

The Lure and Initial Deception

The journey of this infostealer begins innocently enough: a supposed “game cheat” promoted on platforms like YouTube, enticing users with promises of an unfair advantage. Users are then directed to download a Setup.exe file, which masquerades as a legitimate installer. However, this executable is far from harmless. It functions as the initial loader, a crucial first stage in a more complex attack chain designed to compromise personal data.

The Stealthy Payload: A Masterclass in Evasion

Upon execution, the Setup.exe loader deploys its true weapon: a malicious DLL payload. This payload is the core infostealer, engineered to exfiltrate sensitive user information. The startling revelation from the analysis was its complete invisibility to mainstream security tools. While the initial Setup.exe loader was detected by a significant portion of antivirus engines (29 out of 72 on VirusTotal), the subsequent DLL payload achieved a perfect evasion score of 0 out of 64. This stark difference highlights a sophisticated use of anti-analysis techniques, likely involving advanced obfuscation, runtime decryption, or polymorphic code generation that renders it undetectable to static signatures.

Operational Mechanics of the Infostealer

Once active, the infostealer typically targets a wide array of personal data. While the specific exfiltration methods were not fully detailed in the original observation, such threats commonly aim for:

• Browser credentials and stored passwords
• Cryptocurrency wallet keys and seed phrases
• Banking information and credit card details
• System details, installed software, and network configuration
• Session cookies and sensitive files

These sophisticated threats often employ techniques like process injection, API hooking, and encrypted communication channels to send stolen data back to attacker-controlled servers, all while attempting to remain under the radar of endpoint detection and response (EDR) systems.

Implications for Cybersecurity

This incident underscores several critical challenges in modern cybersecurity:

• The Efficacy of Traditional AV: The 0/64 detection rate for the core payload is a stark reminder that traditional signature-based antivirus solutions are often outmatched by sophisticated, constantly evolving threats. Attackers leverage crypters and custom packers to generate unique binaries that bypass known signatures.
• Multi-Stage Attacks: The use of a benign-looking loader to drop a highly evasive payload is a a common and effective tactic. It allows attackers to maintain a lower detection profile for the initial entry point while ensuring the critical component of their attack remains hidden.
• User Vigilance: The lure of “game cheats” or other tempting but unofficial software remains a significant vector for compromise. Users must exercise extreme caution when downloading and executing files from unverified sources.
• Beyond Signatures: Effective detection requires a multi-layered approach incorporating behavioral analysis, machine learning-driven anomaly detection, memory forensics, and robust EDR solutions that can identify malicious activity even when signatures fail.

Conclusion

The case of this multi-stage infostealer serves as a potent illustration of the ongoing arms race between cyber defenders and attackers. It emphasizes that while some security tools can flag initial loaders, the ultimate payload can still operate with alarming stealth. For organizations and individuals alike, relying solely on signature-based detection is no longer sufficient. A proactive, defense-in-depth strategy, coupled with continuous threat intelligence and robust incident response capabilities, is imperative to counter such elusive and dangerous threats.