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.