Name:Internal Vulnerability Scan id:46f946ed-1c78-4e96-9906-c7a4be15e39b version:2 date:2024-10-17 author:Dean Luxton status:experimental type:TTP Description:This analytic detects internal hosts triggering multiple IDS signatures, which may include either more than 25 signatures against a single host or a single signature across over 25 destination IP addresses. Such patterns can indicate active vulnerability scanning activities within the network. By monitoring IDS logs, this detection helps identify and respond to potential vulnerability scanning attempts, enhancing the network's security posture and preventing potential exploits. Data_source:
search:| tstats `security_content_summariesonly` values(IDS_Attacks.action) as action values(IDS_Attacks.src_category) as src_category values(IDS_Attacks.dest_category) as dest_category count from datamodel=Intrusion_Detection.IDS_Attacks where IDS_Attacks.src IN (10.0.0.0/8,192.168.0.0/16,172.16.0.0/12) IDS_Attacks.severity IN (critical, high, medium) by IDS_Attacks.src IDS_Attacks.severity IDS_Attacks.signature IDS_Attacks.dest IDS_Attacks.dest_port IDS_Attacks.transport span=1s _time | `drop_dm_object_name("IDS_Attacks")` | eval gtime=_time | bin span=1h gtime | eventstats count as sevCount by severity src | eventstats count as sigCount by signature src | eval severity=severity +"("+sevCount+")" | eval signature=signature +"("+sigCount+")" | eval dest_port=transport + "/" + dest_port | stats min(_time) as _time values(action) as action dc(dest) as destCount dc(signature) as sigCount values(signature) values(src_category) as src_category values(dest_category) as dest_category values(severity) as severity values(dest_port) as dest_ports by src gtime | fields - gtime | where destCount>25 OR sigCount>25 | `internal_vulnerability_scan_filter`
how_to_implement:For this detection to function effectively, it is essential to ingest IDS/IPS logs that are mapped to the Common Information Model (CIM). These logs provide the necessary security-related telemetry and contextual information needed to accurately identify and analyze potential threats. known_false_positives:Internal vulnerability scanners will trigger this detection. References: drilldown_searches:
: tags: analytic_story: - 'Network Discovery' asset_type:Endpoint confidence:80 impact:80 message:Large volume of IDS signatures triggered by $src$ mitre_attack_id: - 'T1595.002' - 'T1046' observable: name:'src' type:'Hostname' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' risk_score:64 required_fields: - '_time' - 'IDS_Attacks.action' - 'IDS_Attacks.src' - 'IDS_Attacks.dest' - 'IDS_Attacks.dest_port' - 'IDS_Attacks.severity' - 'IDS_Attacks.signature' - 'IDS_Attacks.transport' security_domain:network
