Cisco Cloud Security - Crypto Miner User-Agent Detected

Status: available
Severity: medium
Time window: 15m
Source: github.com/Azure/Azure-Sentinel

'Detects suspicious user agent strings used by crypto miners in proxy logs.'

MITRE ATT&CK coverage

Tactic	Techniques
Command & Control	`T1071.001` Application Layer Protocol: Web Protocols
Exfiltration	`T1041` Exfiltration Over C2 Channel
Impact	`T1496` Resource Hijacking

Rule body

id: b619d1f1-7f39-4c7e-bf9e-afbb46457997
name: Cisco Cloud Security - Crypto Miner User-Agent Detected
description: |
  'Detects suspicious user agent strings used by crypto miners in proxy logs.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: CiscoUmbrellaDataConnector
    dataTypes:
      - Cisco_Umbrella_proxy_CL
queryFrequency: 15m
queryPeriod: 15m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Impact
  - CommandAndControl
  - Exfiltration
relevantTechniques:
  - T1496
  - T1071.001
  - T1041
query: |
  Cisco_Umbrella
  | where EventType == "proxylogs"
  | where HttpUserAgentOriginal contains "XMRig" or HttpUserAgentOriginal contains "ccminer"
  | extend Message = "Crypto Miner User Agent"
  | project TimeGenerated, Message, SrcIpAddr, DstIpAddr, UrlOriginal, HttpUserAgentOriginal
entityMappings:
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: UrlOriginal
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SrcIpAddr
version: 1.1.3
kind: Scheduled

Stages and Predicates

Stage 1: `source`

Cisco_Umbrella

Stage 2: `where`

| where EventType == "proxylogs"

Stage 3: `where`

| where HttpUserAgentOriginal contains "XMRig" or HttpUserAgentOriginal contains "ccminer"

Stage 4: `extend`

| extend Message = "Crypto Miner User Agent"

Stage 5: `project`

| project TimeGenerated, Message, SrcIpAddr, DstIpAddr, UrlOriginal, HttpUserAgentOriginal

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`EventType`	eq	`proxylogs`	`field:"EventType" kind:eq value:"proxylogs"`
`HttpUserAgentOriginal`	contains	`XMRig` `ccminer`	`field:"HttpUserAgentOriginal" kind:contains`

Output fields

These fields are emitted when the rule matches.

Field	Source
`DstIpAddr`	`project`
`HttpUserAgentOriginal`	`project`
`Message`	`project`
`SrcIpAddr`	`project`
`TimeGenerated`	`project`
`UrlOriginal`	`project`

Cisco Cloud Security - Crypto Miner User-Agent Detected

MITRE ATT&CK coverage

Rule body

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: extend

Stage 5: project

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `extend`

Stage 5: `project`