Detect CVE-2025-62221 Microsoft Windows Use After Free Exploitation in Microsoft Sentinel
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
KQL Detection Query
let timeframe = 24h;
let suspiciousProcesses = dynamic(["lsass.exe", "csrss.exe", "winlogon.exe", "services.exe", "svchost.exe"]);
union
(
SecurityEvent
| where TimeGenerated >= ago(timeframe)
| where EventID in (4688, 4689)
| where NewProcessName has_any ("exploit", "shellcode") or
(ParentProcessName in~ (suspiciousProcesses) and NewProcessName !in~ (suspiciousProcesses))
| project TimeGenerated, Computer, Account, NewProcessName, ParentProcessName, CommandLine, EventID
),
(
DeviceEvents
| where TimeGenerated >= ago(timeframe)
| where ActionType in ("ExploitGuardNetworkProtectionAudited", "ExploitGuardNetworkProtectionBlocked", "MemoryAllocationViolation", "UnexpectedKernelWriteAttempt")
| project TimeGenerated, DeviceName, ActionType, InitiatingProcessFileName, InitiatingProcessCommandLine, AdditionalFields
),
(
DeviceProcessEvents
| where TimeGenerated >= ago(timeframe)
| where InitiatingProcessIntegrityLevel == "High" and AccountName != "SYSTEM"
| where ProcessVersionInfoOriginalFileName in~ (suspiciousProcesses) or
(InitiatingProcessParentFileName in~ (suspiciousProcesses) and InitiatingProcessFileName !in~ (suspiciousProcesses))
| project TimeGenerated, DeviceName, AccountName, FileName, InitiatingProcessFileName, InitiatingProcessCommandLine
)
| extend CVE = "CVE-2025-62221"
| sort by TimeGenerated descDetects process anomalies, memory violation events, and privilege escalation patterns consistent with CVE-2025-62221 Windows use-after-free exploitation using Defender for Endpoint and Security Event logs.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate software installers or update agents spawning child processes from system parents
- Security scanning tools or EDR agents performing memory inspection may trigger memory violation events
- Administrative scripts running under elevated context that spawn unusual child processes
- Crash dump collection utilities accessing process memory post-crash
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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Get the full detection package for CVE-2025-62221 including response playbook, investigation guide, and atomic red team tests.