|
| 1 | +[metadata] |
| 2 | +creation_date = "2025/06/11" |
| 3 | +integration = ["endpoint", "windows", "m365_defender", "sentinel_one_cloud_funnel"] |
| 4 | +maturity = "production" |
| 5 | +updated_date = "2025/06/11" |
| 6 | + |
| 7 | +[rule] |
| 8 | +author = ["Elastic"] |
| 9 | +description = """ |
| 10 | +Identifies a suspicious Diagnostics Utility for Internet Explorer child process. This may indicate the successful exploitation of the vulnerability CVE-2025-33053. |
| 11 | +""" |
| 12 | +from = "now-9m" |
| 13 | +index = [ |
| 14 | + "logs-endpoint.events.process-*", |
| 15 | + "winlogbeat-*", |
| 16 | + "logs-windows.sysmon_operational-*", |
| 17 | + "endgame-*", |
| 18 | + "logs-m365_defender.event-*", |
| 19 | + "logs-sentinel_one_cloud_funnel.*", |
| 20 | +] |
| 21 | +language = "eql" |
| 22 | +license = "Elastic License v2" |
| 23 | +name = "Potential CVE-2025-33053 Exploitation" |
| 24 | +note = """## Triage and analysis |
| 25 | +
|
| 26 | +### Investigating Potential CVE-2025-33053 Exploitation |
| 27 | +
|
| 28 | +### Possible investigation steps |
| 29 | +
|
| 30 | +- Review the process details to confirm the suspicious child process was indeed started by iediagcmd.exe. |
| 31 | +- Check any URL file type creation before the alert and review the source of those files. |
| 32 | +- Investigate the process tree and make sure all descendant processes are terminated. |
| 33 | +- Examine the network activity associated with the suspicious process to detect any unauthorized data exfiltration or communication with known malicious IP addresses. |
| 34 | +- Assess the system for any additional indicators of compromise, such as unexpected changes in system files or registry keys, which might suggest a broader attack. |
| 35 | +
|
| 36 | +### False positive analysis |
| 37 | +
|
| 38 | +- This behavior is very rare and should be highly suspicious. |
| 39 | +
|
| 40 | +### Response and remediation |
| 41 | +
|
| 42 | +- Isolate the affected system from the network to prevent further spread of the potential threat and to contain any malicious activity. |
| 43 | +- Terminate the suspicious child process identified in the alert. |
| 44 | +- Conduct a thorough scan of the affected system using updated antivirus or endpoint detection and response (EDR) tools to identify and remove any additional malicious files or processes. |
| 45 | +- Escalate the incident to the security operations center (SOC) or incident response team for further investigation and to determine if the threat is part of a larger attack campaign. |
| 46 | +- Implement additional monitoring and alerting for similar suspicious activities involving explorer.exe to enhance detection capabilities and prevent recurrence. |
| 47 | +- Review and update endpoint security policies to restrict the execution of potentially malicious URL files.""" |
| 48 | +references = [ |
| 49 | + "https://research.checkpoint.com/2025/stealth-falcon-zero-day/", |
| 50 | + "https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-33053", |
| 51 | +] |
| 52 | +risk_score = 73 |
| 53 | +rule_id = "5e23495f-09e2-4484-8235-bdb150d698c9" |
| 54 | +severity = "high" |
| 55 | +tags = [ |
| 56 | + "Domain: Endpoint", |
| 57 | + "OS: Windows", |
| 58 | + "Use Case: Threat Detection", |
| 59 | + "Tactic: Initial Access", |
| 60 | + "Tactic: Defense Evasion", |
| 61 | + "Data Source: Elastic Endgame", |
| 62 | + "Data Source: Elastic Defend", |
| 63 | + "Data Source: Sysmon", |
| 64 | + "Data Source: Microsoft Defender for Endpoint", |
| 65 | + "Data Source: SentinelOne", |
| 66 | + "Resources: Investigation Guide", |
| 67 | +] |
| 68 | +timestamp_override = "event.ingested" |
| 69 | +type = "eql" |
| 70 | + |
| 71 | +query = ''' |
| 72 | +process where host.os.type == "windows" and event.type == "start" and |
| 73 | + process.parent.executable : "C:\\Program Files\\Internet Explorer\\iediagcmd.exe" and |
| 74 | + process.name : ("route.exe", "netsh.exe", "ipconfig.exe", "dxdiag.exe", "conhost.exe", "makecab.exe") and |
| 75 | + process.executable != null and |
| 76 | + not process.executable : ("C:\\Windows\\System32\\route.exe", |
| 77 | + "C:\\Windows\\System32\\netsh.exe", |
| 78 | + "C:\\Windows\\System32\\ipconfig.exe", |
| 79 | + "C:\\Windows\\System32\\dxdiag.exe", |
| 80 | + "C:\\Windows\\System32\\conhost.exe", |
| 81 | + "C:\\Windows\\System32\\makecab.exe") |
| 82 | +''' |
| 83 | + |
| 84 | + |
| 85 | +[[rule.threat]] |
| 86 | +framework = "MITRE ATT&CK" |
| 87 | +[[rule.threat.technique]] |
| 88 | +id = "T1566" |
| 89 | +name = "Phishing" |
| 90 | +reference = "https://attack.mitre.org/techniques/T1566/" |
| 91 | +[[rule.threat.technique.subtechnique]] |
| 92 | +id = "T1566.001" |
| 93 | +name = "Spearphishing Attachment" |
| 94 | +reference = "https://attack.mitre.org/techniques/T1566/001/" |
| 95 | + |
| 96 | +[[rule.threat.technique.subtechnique]] |
| 97 | +id = "T1566.002" |
| 98 | +name = "Spearphishing Link" |
| 99 | +reference = "https://attack.mitre.org/techniques/T1566/002/" |
| 100 | + |
| 101 | +[rule.threat.tactic] |
| 102 | +id = "TA0001" |
| 103 | +name = "Initial Access" |
| 104 | +reference = "https://attack.mitre.org/tactics/TA0001/" |
| 105 | + |
| 106 | + |
| 107 | + |
| 108 | + |
| 109 | +[[rule.threat]] |
| 110 | +framework = "MITRE ATT&CK" |
| 111 | +[[rule.threat.technique]] |
| 112 | +id = "T1218" |
| 113 | +name = "System Binary Proxy Execution" |
| 114 | +reference = "https://attack.mitre.org/techniques/T1218/" |
| 115 | + |
| 116 | + |
| 117 | +[rule.threat.tactic] |
| 118 | +id = "TA0005" |
| 119 | +name = "Defense Evasion" |
| 120 | +reference = "https://attack.mitre.org/tactics/TA0005/" |
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