Detection rules › Kusto

CYFIRMA - Medium severity File Hash Indicators with Monitor Action and Malware

This is a third-party alert feed, not a detection over modeled telemetry. The vendor product raised the finding; this rule forwards it into the SIEM. It is searchable for reference but is excluded from the detection-rule browse and the ATT&CK coverage matrix.

Severity: medium
Time window: 5m
Source: github.com/Azure/Azure-Sentinel

"This KQL query retrieves file hash indicators (MD5, SHA1, SHA256) from the CyfirmaIndicators_CL table within the last 5 minutes. It filters records with a confidence score of 80 or higher, containing file hash patterns, a recommended action of 'Monitor', and roles marked as 'Malware'. Extracted hashes and key threat intelligence details are projected for monitoring and investigation."

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1566.001` Phishing: Spearphishing Attachment
Execution	`T1204` User Execution
Stealth	`T1027` Obfuscated Files or Information, `T1218` System Binary Proxy Execution
Impact	`T1485` Data Destruction, `T1486` Data Encrypted for Impact

Rule body kusto

id: ca16daff-28dd-499d-93fe-0bb232d76d4f
name: CYFIRMA - Medium severity File Hash Indicators with Monitor Action and Malware
description: |
  "This KQL query retrieves file hash indicators (MD5, SHA1, SHA256) from the CyfirmaIndicators_CL table within the last 5 minutes. 
  It filters records with a confidence score of 80 or higher, containing file hash patterns, a recommended action of 'Monitor', and roles marked as 'Malware'. 
  Extracted hashes and key threat intelligence details are projected for monitoring and investigation."
version: 1.0.1
kind: Scheduled
severity: Medium
enabled: false
requiredDataConnectors:
  - connectorId: CyfirmaCyberIntelligenceDC
    dataTypes:
      - CyfirmaIndicators_CL
query: |
  // File Hash Indicators with Monitor Action and Malware
  let timeFrame = 5m;
  CyfirmaIndicators_CL 
  | where  (ConfidenceScore < 80 and ConfidenceScore >= 50)
      and TimeGenerated between (ago(timeFrame) .. now())
      and pattern contains 'file:hashes' and RecommendedActions has 'Monitor' and (Roles contains 'Malware')
  | extend MD5 = extract(@"file:hashes\.md5\s*=\s*'([a-fA-F0-9]{32})'", 1, pattern)
  | extend SHA1 = extract(@"file:hashes\.'SHA-1'\s*=\s*'([a-fA-F0-9]{40})'", 1, pattern)
  | extend SHA256 = extract(@"file:hashes\.'SHA-256'\s*=\s*'([a-fA-F0-9]{64})'", 1, pattern)
  | extend
      Algo_MD5='md5',
      Algo_SHA1= 'SHA1',
      Algo_SHA256='SHA256',
      ProviderName = 'CYFIRMA',
      ProductName = 'DeCYFIR/DeTCT'
  | project  
      MD5,
      Algo_MD5,
      SHA1,
      Algo_SHA1,
      SHA256,
      Algo_SHA256,
      ThreatActors,
      Sources,
      RecommendedActions,
      Roles,
      Country,
      name,
      Description,
      ConfidenceScore,
      SecurityVendors,
      IndicatorID,
      created,
      modified,
      valid_from,
      Tags,
      ThreatType,
      TimeGenerated,
      ProductName,
      ProviderName
queryFrequency: 5m
queryPeriod: 5m
triggerOperator: GreaterThan
triggerThreshold: 0
suppressionDuration: 5m
suppressionEnabled: true
tactics:
  - DefenseEvasion
  - InitialAccess
  - Impact
  - Execution
relevantTechniques:
  - T1027
  - T1486
  - T1204
  - T1485
  - T1218
  - T1566.001
alertDetailsOverride:
  alertDisplayNameFormat: "High-Confidence File Hash Indicators with Monitor Action and Malware - {{name}} "
  alertDescriptionFormat: "{{Description}} - {{name}} "
  alertDynamicProperties:
    - alertProperty: ProviderName
      value: ProviderName
    - alertProperty: ProductName
      value: ProductName
customDetails:
  ThreatActors: ThreatActors
  Sources: Sources
  RecommendedActions: RecommendedActions
  Roles: Roles
  Country: Country
  Description: Description
  ConfidenceScore: ConfidenceScore
  SecurityVendors: SecurityVendors
  IndicatorID: IndicatorID
  created: created
  modified: modified
  valid_from: valid_from
  Tags: Tags
  ThreatType: ThreatType
  TimeGenerated: TimeGenerated
entityMappings:
  - entityType: FileHash
    fieldMappings:
      - identifier: Algorithm
        columnName: Algo_MD5
      - identifier: Value
        columnName: MD5
  - entityType: FileHash
    fieldMappings:
      - identifier: Algorithm
        columnName: Algo_SHA1
      - identifier: Value
        columnName: SHA1
  - entityType: FileHash
    fieldMappings:
      - identifier: Algorithm
        columnName: Algo_SHA256
      - identifier: Value
        columnName: SHA256
incidentConfiguration:
  createIncident: true
  groupingConfiguration:
    enabled: false
    reopenClosedIncident: false
    lookbackDuration: PT5H
    matchingMethod: AllEntities
eventGroupingSettings:
  aggregationKind: AlertPerResult

Stages and Predicates

Parameters

let timeFrame = 5m;

Stage 1: `source`

CyfirmaIndicators_CL

Stage 2: `where`

| where  (ConfidenceScore < 80 and ConfidenceScore >= 50)
    and TimeGenerated between (ago(timeFrame) .. now())
    and pattern contains 'file:hashes' and RecommendedActions has 'Monitor' and (Roles contains 'Malware')

Stage 3: `extend` (4 consecutive steps)

| extend MD5 = extract(@"file:hashes\.md5\s*=\s*'([a-fA-F0-9]{32})'", 1, pattern)
| extend SHA1 = extract(@"file:hashes\.'SHA-1'\s*=\s*'([a-fA-F0-9]{40})'", 1, pattern)
| extend SHA256 = extract(@"file:hashes\.'SHA-256'\s*=\s*'([a-fA-F0-9]{64})'", 1, pattern)
| extend
    Algo_MD5='md5',
    Algo_SHA1= 'SHA1',
    Algo_SHA256='SHA256',
    ProviderName = 'CYFIRMA',
    ProductName = 'DeCYFIR/DeTCT'

Stage 4: `project`

| project  
    MD5,
    Algo_MD5,
    SHA1,
    Algo_SHA1,
    SHA256,
    Algo_SHA256,
    ThreatActors,
    Sources,
    RecommendedActions,
    Roles,
    Country,
    name,
    Description,
    ConfidenceScore,
    SecurityVendors,
    IndicatorID,
    created,
    modified,
    valid_from,
    Tags,
    ThreatType,
    TimeGenerated,
    ProductName,
    ProviderName

Indicators

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
`ConfidenceScore`	ge	`50` transforms: `cased`
`ConfidenceScore`	lt	`80` transforms: `cased`
`RecommendedActions`	match	`Monitor` transforms: `term`
`Roles`	contains	`Malware`
`pattern`	contains	`file:hashes`

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
`Algo_MD5`	`project`
`Algo_SHA1`	`project`
`Algo_SHA256`	`project`
`ConfidenceScore`	`project`
`Country`	`project`
`Description`	`project`
`IndicatorID`	`project`
`MD5`	`project`
`ProductName`	`project`
`ProviderName`	`project`
`RecommendedActions`	`project`
`Roles`	`project`
`SHA1`	`project`
`SHA256`	`project`
`SecurityVendors`	`project`
`Sources`	`project`
`Tags`	`project`
`ThreatActors`	`project`
`ThreatType`	`project`
`TimeGenerated`	`project`
`created`	`project`
`modified`	`project`
`name`	`project`
`valid_from`	`project`

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

CYFIRMA - Medium severity File Hash Indicators with Monitor Action and Malware

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend` (4 consecutive steps)

Stage 4: `project`

Indicators

Output fields

Keyboard shortcuts

Search operators

CYFIRMA - Medium severity File Hash Indicators with Monitor Action and Malware

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: source

Stage 2: where

Stage 3: extend (4 consecutive steps)

Stage 4: project

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend` (4 consecutive steps)

Stage 4: `project`