Detection rules › Kusto
Cisco WSA - Multiple attempts to download unwanted file
'Detects when multiple attempts to download unwanted file occur.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access |
Rule body
id: 46b6c6fc-2c1a-4270-be10-9d444d83f027
name: Cisco WSA - Multiple attempts to download unwanted file
description: |
'Detects when multiple attempts to download unwanted file occur.'
severity: Medium
status: Available
requiredDataConnectors:
- connectorId: SyslogAma
datatypes:
- Syslog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- InitialAccess
relevantTechniques:
- T1189
query: |
let threshold = 2;
CiscoWSAEvent
| where DvcAction =~ 'BLOCK_ADMIN_FILE_TYPE'
| summarize i_src = makeset(SrcIpAddr) by UrlOriginal, bin(TimeGenerated, 15m)
| where array_length(i_src) >= threshold
| extend IPCustomEntity = i_src, UrlCustomEntity = UrlOriginal
entityMappings:
- entityType: IP
fieldMappings:
- identifier: Address
columnName: IPCustomEntity
- entityType: URL
fieldMappings:
- identifier: Url
columnName: UrlCustomEntity
version: 1.0.2
kind: Scheduled
Stages and Predicates
Parameters
let threshold = 2;
Stage 1: source
CiscoWSAEvent
Stage 2: where
| where DvcAction =~ 'BLOCK_ADMIN_FILE_TYPE'
Stage 3: summarize
| summarize i_src = makeset(SrcIpAddr) by UrlOriginal, bin(TimeGenerated, 15m)
Stage 4: where
| where array_length(i_src) >= threshold
Stage 5: extend
| extend IPCustomEntity = i_src, UrlCustomEntity = UrlOriginal
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
DvcAction | eq |
| field:"DvcAction" kind:eq value:"BLOCK_ADMIN_FILE_TYPE" |
Output fields
These fields are emitted when the rule matches.
| Field | Source |
|---|---|
UrlOriginal | summarize |
i_src | summarize |
IPCustomEntity | extend |
UrlCustomEntity | extend |