LNK files

Winsage
April 30, 2025
Security researcher Nafiez has discovered a vulnerability in Windows LNK files that allows remote code execution without user interaction. Microsoft has chosen not to address this issue, stating it does not meet their security servicing criteria. The vulnerability exploits specific components of LNK files, enabling attackers to create malicious shortcuts that initiate silent network connections when a user accesses a folder containing them. The exploit involves manipulating the HasArguments flag, EnvironmentVariableDataBlock, and embedding UNC paths. Microsoft defends its inaction by citing the Mark of the Web (MOTW) feature as adequate protection, despite concerns from security experts about its effectiveness. Previous vulnerabilities in LNK files have been addressed by Microsoft, and the availability of proof-of-concept code raises fears of potential exploitation by malicious actors.
Winsage
April 17, 2025
Cybercriminals are exploiting a vulnerability in Windows systems known as CVE-2025-24054, which involves NTLM hash disclosure through spoofing techniques. This flaw allows attackers to leak NTLM hashes, leading to privilege escalation and lateral movement within networks. It is triggered when a user extracts a ZIP archive containing a malicious .library-ms file, causing Windows Explorer to initiate SMB authentication requests that expose NTLMv2-SSP hashes. Exploitation of this vulnerability began shortly after a security patch was released on March 11, 2025, with campaigns targeting government and private institutions in Poland and Romania. These campaigns utilized spear-phishing emails containing malicious ZIP archives, which, when interacted with, leaked NTLM hashes. The malicious files included various types designed to initiate SMB connections to attacker-controlled servers, allowing for pass-the-hash attacks and privilege escalation. The stolen hashes were sent to servers in several countries, indicating potential links to state-sponsored groups. One campaign involved Dropbox links that exploited the vulnerability upon user interaction. Microsoft has recommended immediate patching, enhancing network defenses, user education, network segmentation, and regular security audits to mitigate risks associated with this vulnerability.
Winsage
March 24, 2025
A vulnerability in Microsoft Windows' handling of link files (.lnk) has been exploited by state-sponsored hackers from North Korea, Russia, Iran, and China for espionage and data theft. This flaw allows malicious payloads to be embedded in seemingly harmless links, enabling remote execution of arbitrary code and unauthorized access to compromised systems. Nearly 1,000 malicious .lnk files have been identified, with around 70% of attacks focused on espionage and information theft, particularly targeting government and financial institutions. The malicious commands are difficult to detect, complicating protection efforts for organizations. ZDI recommends increased awareness and the use of endpoint and network protection tools to mitigate the threat.
Winsage
March 22, 2025
A zero-day vulnerability in Windows shortcut (.lnk) files has been exploited by state-sponsored hacking groups since 2017, allowing attackers to execute arbitrary code on compromised systems. Microsoft has classified this vulnerability as “not meeting the bar servicing,” meaning no security updates will be issued. Trend Micro tracks it as ZDI-CAN-25373 and has linked it to cyber-espionage campaigns involving 11 nation-state actors from countries like North Korea, Iran, Russia, and China. Nearly 1,000 malicious .lnk samples exploiting this flaw have been identified, with many more potentially undetected. Attackers often use phishing emails to deliver these malicious files, which can download additional malware, granting full control over the compromised machine. Organizations are advised to scan their systems and implement security measures against this vulnerability.
Winsage
March 20, 2025
Almost a dozen state-sponsored threat groups from nations including China, Russia, Iran, and North Korea are exploiting a security vulnerability in Microsoft Windows, identified as ZDI-CAN-25373, to conduct espionage and gather sensitive information. This vulnerability affects how Windows handles .lnk files, allowing attackers to execute hidden malicious commands. Since 2017, these groups have targeted government, military, and critical infrastructure organizations globally, with 11 state-sponsored groups identified, primarily focusing on espionage (70%) and financial motives (20%). North Korea accounts for 45.5% of the exploitation, with Iran and Russia at 18.2% each, and China at 18.1%. The United States has experienced the most attacks (343 incidents), followed by Canada (39), Russia (25), and South Korea (23). Despite being notified, Microsoft does not plan to issue a patch for this vulnerability, categorizing it as "low severity."
Tech Optimizer
December 19, 2024
Cyber attackers are increasingly using malicious LNK files, which disguise themselves as harmless shortcuts, as an infection vector in 2024. Security experts, particularly Cyble Research and Intelligence Labs (CRIL), have noted a significant rise in this tactic. Attackers leverage LNK files to gain access to systems, triggering malicious actions that can deploy advanced malware. This method reflects a shift in attack vectors aimed at bypassing traditional security measures. One primary technique in these attacks is the exploitation of Living-off-the-Land Binaries (LOLBins), which are trusted system binaries manipulated to execute harmful commands without external malware. Attackers have refined their methods to evade detection by endpoint detection and response (EDR) solutions. Recent campaigns have incorporated SSH commands within malicious LNK files, allowing attackers to establish persistent connections and download malicious files from remote servers. This use of SSH is concerning as it is not typically associated with Windows systems, making it harder for conventional security measures to detect. Threat actors have also used SSH commands to execute malicious PowerShell or CMD commands indirectly through LNK files. For example, a malicious LNK file was found to trigger a PowerShell script that downloaded a malicious payload. Advanced Persistent Threat (APT) groups, known for their long-term cyber espionage, are increasingly utilizing these techniques, with groups like Transparent Tribe deploying stealer malware using similar methods. The combination of LNK files and SSH commands presents a significant threat to organizations, necessitating enhanced monitoring and detection systems to identify abnormal activities. Security teams must evolve EDR solutions to recognize malicious SSH and SCP activity, especially in environments where SSH is not commonly used. Additionally, organizations should restrict the use of legitimate SSH utilities and disable unnecessary features to minimize the attack surface.
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