Detect CVE-2024-43451: Windows NTLM Hash Disclosure via File Interaction in Sumo Logic CSE
CVE-2024-43451 is a Windows NTLM hash disclosure vulnerability (NTLMv2 spoofing) affecting Windows 10, Windows 11, and Windows Server 2008-2025. Minimal user interaction with a malicious file (right-click, open, or preview) triggers an outbound NTLM authentication request to an attacker-controlled server, leaking the victim's NTLMv2 hash. The hash can be cracked offline or used in relay attacks. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.
MITRE ATT&CK
Sumo Detection Query
_sourceCategory=windows/security OR _sourceCategory=windows/sysmon
| where EventID in ("4648", "4624", "5156", "4688")
| if (EventID == "4688", CommandLine, "") as process_cmd
| if (matches(process_cmd, "(?i)\.(url|lnk|scf|library-ms|searchConnector-ms)"), 1, 0) as suspicious_file_access
| if (EventID in ("5156", "4648"), DestAddress, "") as dest_ip
| where dest_ip != ""
| where !matches(dest_ip, "^(10\\.|172\\.(1[6-9]|2[0-9]|3[01])\\.|192\.168\.)") and dest_ip != "127.0.0.1"
| timeslice 5m
| stats count as connection_count, count_distinct(dest_ip) as unique_ext_ips, max(suspicious_file_access) as had_suspicious_file by _timeslice, Computer, SubjectUserName
| where connection_count > 0 and had_suspicious_file == 1
| sort by _timeslice descSumo Logic query identifying hosts that both interacted with suspicious file types (triggering potential NTLM leakage) and initiated outbound SMB connections to non-private IPs within the same 5-minute window, indicative of CVE-2024-43451 exploitation.
Data Sources
False Positives & Tuning
- Automated file processing systems handling .lnk files as part of legitimate workflows
- Remote desktop or virtual desktop infrastructure scenarios with non-standard routing
- Cloud sync clients (OneDrive, SharePoint) interacting with shortcut files and making SMB calls
- Penetration test activity conducted without prior notification to the SOC
Other platforms for CVE-2024-43451
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1NTLM Hash Disclosure via Malicious .url File
Expected signal: Sysmon EventID 11 (file creation for .url file), Sysmon EventID 3 (network connection from explorer.exe to ATTACKER_IP:445), Windows Security EventID 4648 (explicit credential use targeting ATTACKER_IP), Responder captures NTLMv2 hash
- Test 2NTLM Hash Disclosure via Malicious .lnk Shortcut
Expected signal: Sysmon EventID 11 (LNK creation), Sysmon EventID 3 (explorer.exe → ATTACKER_IP:445), Windows Security EventID 4648 with LogonType=3 and TargetServerName=ATTACKER_IP
- Test 3NTLM Hash Disclosure via Malicious .scf (Shell Command File)
Expected signal: Sysmon EventID 3 from explorer.exe to ATTACKER_IP:445 without any explicit user action beyond folder view, Windows Security EventID 4648 capturing NTLMv2 exchange, network PCAP showing full NTLM handshake
Unlock Pro Content
Get the full detection package for CVE-2024-43451 including response playbook, investigation guide, and atomic red team tests.