Detects exploits for CVE-2015-1674

Hunt Hypothesis

Exploitation of the CVE-2015-1674 vulnerability could indicate an adversary leveraging a known remote code execution flaw to gain unauthorized access to systems. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate potential compromise from legacy vulnerabilities that may still exist in their environment.

YARA Rule

rule CVE_2015_1674_CNGSYS {
	meta:
		description = "Detects exploits for CVE-2015-1674"
		author = "Florian Roth"
		reference = "http://www.binvul.com/viewthread.php?tid=508"
		reference2 = "https://github.com/Neo23x0/Loki/blob/master/signatures/exploit_cve_2015_1674.yar"
		date = "2015-05-14"
		hash = "af4eb2a275f6bbc2bfeef656642ede9ce04fad36"
	strings:
		$s1 = "\\Device\\CNG" fullword wide
		
		$s2 = "GetProcAddress" fullword ascii
		$s3 = "LoadLibrary" ascii
		$s4 = "KERNEL32.dll" fullword ascii
		$s5 = "ntdll.dll" fullword ascii
	condition:
		uint16(0) == 0x5a4d and filesize < 60KB and all of them
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

• Microsoft Defender for Endpoint — Custom indicators / advanced hunting
• Email Gateway — Attachment scanning
• File Share Monitoring — Periodic scanning of shared drives
• YARA CLI — Manual threat hunting on endpoints

This rule contains 5 string patterns in its detection logic.

References

• http://www.binvul.com/viewthread.php?tid=508
• Source Rule

False Positive Guidance

• Scenario: A system administrator is using msiexec to install a legitimate Windows update or patch.
  Filter/Exclusion: Check for msiexec with known update package names (e.g., Windows6.1-KB2828353-x86.msi), or filter by process parent (e.g., services.exe or task scheduler).

• Scenario: A scheduled job runs net use to map a network drive for backup purposes.
  Filter/Exclusion: Exclude processes with net use where the command line includes \\server\share\backup or similar known backup paths.

• Scenario: A security tool like Sysmon or Process Monitor is generating logs that include the exploit-related command line arguments.
  Filter/Exclusion: Exclude events where the process name matches the security tool (e.g., Sysmon64.exe, Procmon.exe).

• Scenario: A user is running a legitimate script that uses cmd.exe with the /c switch to execute a command for system maintenance.
  Filter/Exclusion: Filter out commands that match known maintenance scripts (e.g., schtasks.exe /run or wbadmin commands).

• Scenario: A database administrator is using sqlcmd to execute a script that includes the exploit string due to a misconfigured script.
  Filter/Exclusion: Exclude commands where the process is sqlcmd and the command line includes known database maintenance scripts or paths.