Detect CVE-2025-62221 Microsoft Windows Use After Free Exploitation in Elastic Security
Detects exploitation attempts of CVE-2025-62221, a use-after-free vulnerability in Microsoft Windows. This class of memory corruption flaw allows attackers to execute arbitrary code by manipulating freed memory objects. As a CISA KEV entry, active exploitation in the wild has been confirmed. Detection focuses on anomalous process behavior, kernel-mode memory corruption indicators, crash telemetry, and privilege escalation patterns consistent with UAF exploitation chains.
MITRE ATT&CK
- Tactic
- Privilege Escalation Execution
Elastic Detection Query
sequence by host.name with maxspan=5m
[process where event.action == "start" and
process.parent.name in ("lsass.exe", "csrss.exe", "winlogon.exe", "services.exe", "svchost.exe") and
not process.name in ("lsass.exe", "csrss.exe", "winlogon.exe", "services.exe", "svchost.exe",
"conhost.exe", "WerFault.exe", "wermgr.exe")]
[any where event.category == "process" and
(process.token.integrity_level_name == "high" or process.token.integrity_level_name == "system") and
user.name != "SYSTEM" and user.name != "LOCAL SERVICE" and user.name != "NETWORK SERVICE"]EQL sequence detection correlating anomalous child process creation from Windows system processes followed by elevated token acquisition, indicative of CVE-2025-62221 UAF privilege escalation.
Data Sources
Required Tables
False Positives & Tuning
- Windows Update processes spawning child utilities from svchost.exe during patch cycles
- System management frameworks like SCCM or Intune spawning agents from service parents
- Security software performing token inspection or integrity level checks as part of normal operations
Other platforms for CVE-2025-62221
Testing Methodology
Validate this detection against 4 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 1Simulate UAF-style anomalous child process from lsass.exe parent (lab only)
Expected signal: Sysmon Event ID 1 with ParentImage pointing to lsass.exe and Image of cmd.exe; Windows Security EventID 4688 with anomalous parent-child relationship
- Test 2WER crash trigger on system process to simulate pre-exploit crash artifacts
Expected signal: Windows Event ID 1000 (Application Error) and 1001 (Windows Error Reporting) in Application event log; WER report created in %LOCALAPPDATA%\Microsoft\Windows\WER\ReportQueue
- Test 3Elevated token process launch from spoofed system parent context
Expected signal: Sysmon Event ID 1 showing cmd.exe with IntegrityLevel=System spawned by psexec service; Windows Security EventID 4688 with elevated token; EventID 4672 (special privileges assigned to new logon)
- Test 4Heap spray pattern simulation via PowerShell memory allocation
Expected signal: PowerShell Script Block Logging (EventID 4104) capturing the allocation loop; potential AMSI or Defender behavioral alert on large sequential memory allocation patterns
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