The Rising Threat of Malicious LNK Files in Modern Cyber Attacks

Windows shortcut files (LNK) have become a preferred attack vector for threat actors following Microsoft’s decision to disable macros by default in Office documents. This shift has led to a surge in campaigns leveraging LNK files to deliver malware, with groups like Emotet and QBot adopting the technique. The trend represents a significant evolution in initial access strategies, requiring updated detection and mitigation approaches from security teams.

Executive Summary for Security Leadership

The transition from macro-based attacks to LNK file abuse marks a tactical adaptation by threat actors to bypass modern security controls. Recent campaigns demonstrate that 87.2% of malicious LNK files abuse Windows Explorer (explorer.exe) as part of their execution chain, often leading to PowerShell-based payloads. Security teams should prioritize monitoring non-executable file execution patterns and implement specific controls around LNK file handling, particularly in email attachments.

Threat Vector: Malicious LNK files now account for majority of initial access attempts
Primary Abuse: Windows LOLBins (explorer.exe, powershell.exe, wscript.exe)
Common Payloads: Emotet, QBot, and North Korean APT malware
Detection Gap: 99.9% of malicious LNK files use random filenames
Commercial Tools: QuantumBuilder ($100-$189) used to create obfuscated LNK files

Technical Analysis of LNK File Attacks

The attack chain typically begins with a phishing email containing a ZIP archive with an LNK file. When executed, the shortcut file leverages Windows components like explorer.exe to launch secondary payloads. SentinelOne research shows that threat actors frequently combine this with script files (.vbs, .js) masquerading as documents to evade detection. The mLNK tool and similar builder kits enable attackers to create sophisticated LNK files that bypass traditional security controls.

North Korean APT groups like Kimsuky have incorporated LNK files into their campaigns targeting South Korean organizations. These attacks often use Korean-language lures and Dropbox-hosted PowerShell scripts (e.g., system_first.ps1) for initial reconnaissance. The scripts employ junk code and string concatenation for obfuscation, making static analysis more challenging.

Detection and Mitigation Strategies

Effective detection requires monitoring for suspicious process chains involving LNK files. Key indicators include LNK files executing non-EXE files, especially when combined with PowerShell or WScript. Security teams should implement the following measures:

Control	Implementation
Email Filtering	Block LNK files in email attachments
Process Monitoring	Alert on explorer.exe spawning script interpreters
PowerShell Logging	Enable script block logging and transcription
Application Control	Restrict script execution from temporary directories

For organizations handling sensitive data, additional measures like disabling LNK file execution entirely may be warranted. This can be implemented through Group Policy or endpoint protection platforms. Regular user awareness training about the risks of opening unexpected attachments remains critical.

Broader Implications for Enterprise Security

The shift to LNK file attacks reflects the ongoing cat-and-mouse game between attackers and defenders. As Microsoft hardens default configurations in Office products, threat actors pivot to alternative techniques that exploit trusted Windows components. This pattern suggests that future security investments should focus more on behavior monitoring rather than signature-based detection.

The emergence of commercial LNK file builders indicates this attack vector has become commoditized, making it accessible to less sophisticated threat actors. Security teams should expect to see broader adoption across the threat landscape, including by ransomware groups and initial access brokers.

Conclusion

The rise of LNK file-based attacks represents a significant shift in the threat landscape that requires updated defensive strategies. Organizations should review their email security controls, enhance process monitoring, and consider restricting LNK file execution in high-risk environments. As threat actors continue to adapt, security teams must prioritize detection capabilities that focus on malicious behavior patterns rather than specific file types.

References

“Who Needs Macros? Threat Actors Pivot to Abusing Explorer and Other LOLBins via Windows Shortcuts,” SentinelOne, 2025.
Small, S., “The Rise of LNK Files and Ways to Detect Them,” LinkedIn, 2025.
“Analyzing DEEP#DRIVE: North Korean Threat Actors Observed Exploiting Trusted Platforms for Targeted Attacks,” Securonix, 2025.