MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Reconnaissance |
Rule body
id: e087d4fb-af0b-4e08-a067-b9ba9e5f8840
name: OCI - SSH scanner
description: |
'Detects possible SSH scanning activity.'
severity: High
status: Available
requiredDataConnectors:
- connectorId: OracleCloudInfrastructureLogsConnector
dataTypes:
- OCILogs
- connectorId: OracleCloudInfraConnector
dataTypes:
- OCI_LogsV2_CL
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- Reconnaissance
relevantTechniques:
- T1595
query: |
let threshold = 5;
OCILogs
| where EventType contains 'vcn.flowlogs'
| where data_action_s =~ 'REJECT'
| where ipv4_is_private(DstIpAddr)
| where ipv4_is_private(SrcIpAddr) == False
| where DstPortNumber == 22
| summarize p_count = dcount(DstIpAddr) by SrcIpAddr, bin(TimeGenerated, 5m)
| where p_count > threshold
| extend IPCustomEntity = SrcIpAddr
entityMappings:
- entityType: IP
fieldMappings:
- identifier: Address
columnName: IPCustomEntity
version: 1.0.2
kind: Scheduled
Stages and Predicates
Parameters
let threshold = 5;
Stage 1: source
OCILogs
Stage 2: where
| where EventType contains 'vcn.flowlogs'
Stage 3: where
| where data_action_s =~ 'REJECT'
Stage 4: where
| where ipv4_is_private(DstIpAddr)
Stage 5: where
| where ipv4_is_private(SrcIpAddr) == False
Stage 6: where
| where DstPortNumber == 22
Stage 7: summarize
| summarize p_count = dcount(DstIpAddr) by SrcIpAddr, bin(TimeGenerated, 5m)
Stage 8: where
| where p_count > threshold
Stage 9: extend
| extend IPCustomEntity = SrcIpAddr
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
SrcIpAddr | cidr_match | 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, 169.254.0.0/16, 127.0.0.0/8 | excludes:SrcIpAddr |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
DstIpAddr | cidr_match |
| field:"dest_ip" kind:cidr_match |
DstPortNumber | eq |
| field:"DstPortNumber" kind:eq value:"22" |
EventType | contains |
| field:"EventType" kind:contains value:"vcn.flowlogs" |
data_action_s | eq |
| field:"data_action_s" kind:eq value:"REJECT" |
p_count | gt |
| field:"p_count" kind:gt value:"5" |
Output fields
These fields are emitted when the rule matches.
| Field | Source |
|---|---|
SrcIpAddr | summarize |
p_count | summarize |
IPCustomEntity | extend |