Detection rules › Kusto
Cisco ASA - threat detection message fired
'Identifies when the Cisco ASA Threat Detection engine fired an alert based on malicious activity occurring on the network inicated by DeviceEventClassID 733101-733105 Resources: https://www.cisco.com/c/en/us/td/docs/security/asa/syslog/b_syslog/syslogs9.html Details on how to further troubleshoot/investigate: https://www.cisco.com/c/en/us/support/docs/security/asa-5500-x-series-next-generation-firewalls/113685-asa-threat-detection.html'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Discovery | T1046 Network Service Discovery |
| Impact | T1498 Network Denial of Service |
Rule body kusto
id: 795edf2d-cf3e-45b5-8452-fe6c9e6a582e
name: Cisco ASA - threat detection message fired
description: |
'Identifies when the Cisco ASA Threat Detection engine fired an alert based on malicious activity occurring on the network inicated by DeviceEventClassID 733101-733105
Resources: https://www.cisco.com/c/en/us/td/docs/security/asa/syslog/b_syslog/syslogs9.html
Details on how to further troubleshoot/investigate: https://www.cisco.com/c/en/us/support/docs/security/asa-5500-x-series-next-generation-firewalls/113685-asa-threat-detection.html'
severity: Medium
status: Available
requiredDataConnectors:
- connectorId: CiscoAsaAma
dataTypes:
- CommonSecurityLog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- Discovery
- Impact
relevantTechniques:
- T1046
- T1498
query: |
CommonSecurityLog
| where isempty(CommunicationDirection)
| where DeviceEventClassID in ("733101","733102","733103","733104","733105")
| extend HostName = tostring(split(DeviceName, ".")[0]), DomainIndex = toint(indexof(DeviceName, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)
entityMappings:
- entityType: Host
fieldMappings:
- identifier: FullName
columnName: DeviceName
- entityType: IP
fieldMappings:
- identifier: Address
columnName: SourceIP
version: 1.0.3
kind: Scheduled
Stages and Predicates
Stage 1: source
CommonSecurityLog
Stage 2: where
| where isempty(CommunicationDirection)
Stage 3: where
| where DeviceEventClassID in ("733101","733102","733103","733104","733105")
Stage 4: extend
| extend HostName = tostring(split(DeviceName, ".")[0]), DomainIndex = toint(indexof(DeviceName, '.'))
Stage 5: extend
| extend HostNameDomain = iff(DomainIndex != -1, substring(DeviceName, DomainIndex + 1), DeviceName)
HostNameDomain =DomainIndex != -1substring(DeviceName, (DomainIndex + 1))DeviceNameIndicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
CommunicationDirection | is_null | |
DeviceEventClassID | in |
|
Output fields
Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.
| Field | Source |
|---|---|
DomainIndex | extend |
HostName | extend |
HostNameDomain | extend |