Name:Detect Computer Changed with Anonymous Account id:1400624a-d42d-484d-8843-e6753e6e3645 version:4 date:2024-10-17 author:Rod Soto, Jose Hernandez, Splunk status:experimental type:Hunting Description:The following analytic detects changes to computer accounts using an anonymous logon. It leverages Windows Security Event Codes 4742 (Computer Change) and 4624 (Successful Logon) with the TargetUserName set to "ANONYMOUS LOGON" and LogonType 3. This activity is significant because anonymous logons should not typically be modifying computer accounts, indicating potential unauthorized access or misconfiguration. If confirmed malicious, this could allow an attacker to alter computer accounts, potentially leading to privilege escalation or persistent access within the network. Data_source:
-Windows Event Log Security 4624
-Windows Event Log Security 4742
search:`wineventlog_security` EventCode=4624 OR EventCode=4742 TargetUserName="ANONYMOUS LOGON" LogonType=3 | stats count values(host) as host, values(TargetDomainName) as Domain, values(user) as user | `detect_computer_changed_with_anonymous_account_filter`
how_to_implement:This search requires audit computer account management to be enabled on the system in order to generate Event ID 4742. We strongly recommend that you specify your environment-specific configurations (index, source, sourcetype, etc.) for Windows Event Logs. Replace the macro definition with configurations for your Splunk environment. The search also uses a post-filter macro designed to filter out known false positives. known_false_positives:None thus far found References: -https://www.lares.com/blog/from-lares-labs-defensive-guidance-for-zerologon-cve-2020-1472/ drilldown_searches:
: tags: analytic_story: - 'Detect Zerologon Attack' asset_type:Windows confidence:70 cve: - 'CVE-2020-1472' impact:70 message:The following $EventCode$ occurred on $dest$ by $user$ with Logon Type 3, which may be indicative of the an account or group being changed by an anonymous account. mitre_attack_id: - 'T1210' observable: name:'user' type:'User' - role: - 'Victim' name:'dest' type:'Hostname' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'EventCode' - 'TargetUserName' - 'LogonType' - 'TargetDomainName' - 'user' risk_score:49 security_domain:endpoint
