Detection rules › Kusto

CYFIRMA - Medium severity Trojan File Hash Indicators with Block Action Rule

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 extracts file hash indicators associated with Trojan activity from the CyfirmaIndicators_CL table. It specifically targets indicators containing file hashes linked to Trojan behavior and retrieves MD5, SHA1, and SHA256 values. The query also includes contextual threat intelligence such as threat actors, tags, sources, and geolocation information."

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1566.001` Phishing: Spearphishing Attachment
Execution	`T1204` User Execution
Persistence	`T1547.001` Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder
Stealth	`T1027` Obfuscated Files or Information
Credential Access	`T1003` OS Credential Dumping
Command & Control	`T1071` Application Layer Protocol

Rule body kusto

id: 25686f44-5f5f-4388-95e2-eea244481438
name: CYFIRMA - Medium severity Trojan File Hash Indicators with Block Action Rule
description: |
  "This KQL query extracts file hash indicators associated with Trojan activity from the CyfirmaIndicators_CL table. 
  It specifically targets indicators containing file hashes linked to Trojan behavior and retrieves MD5, SHA1, and SHA256 values. 
  The query also includes contextual threat intelligence such as threat actors, tags, sources, and geolocation information."
version: 1.0.1
kind: Scheduled
severity: Medium
enabled: false
requiredDataConnectors:
  - connectorId: CyfirmaCyberIntelligenceDC
    dataTypes:
      - CyfirmaIndicators_CL
query: |
  //Trojan File Hash Indicators with Block Action
  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 'Block' and (Roles has 'Trojan')
  | 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:
  - InitialAccess
  - Execution
  - Persistence
  - DefenseEvasion
  - CommandAndControl
  - CredentialAccess
relevantTechniques:
  - T1566
  - T1204
  - T1547
  - T1027
  - T1071
  - T1003
  - T1566.001
  - T1547.001
alertDetailsOverride:
  alertDisplayNameFormat: "High-Confidence Trojan File Hash Indicators with Block Action Rule - {{name}} "
  alertDescriptionFormat: "{{Description}} - {{name}} "
  alertDynamicProperties:
    - alertProperty: ProductName
      value: ProductName
    - alertProperty: ProviderName
      value: ProviderName
customDetails:
  ThreatActors: ThreatActors
  Sources: Sources
  RecommendedActions: RecommendedActions
  Roles: Roles
  Country: Country
  Description: Description
  ConfidenceScore: ConfidenceScore
  SecurityVendors: SecurityVendors
  IndicatorID: IndicatorID
  created: created
  modified: modified
  ValidFrom: valid_from
  Tags: Tags
  ThreatType: ThreatType
  TimeGenerated: TimeGenerated
entityMappings:
  - entityType: FileHash
    fieldMappings:
      - identifier: Value
        columnName: MD5
      - identifier: Algorithm
        columnName: Algo_MD5
  - entityType: FileHash
    fieldMappings:
      - identifier: Value
        columnName: SHA1
      - identifier: Algorithm
        columnName: Algo_SHA1
  - entityType: FileHash
    fieldMappings:
      - identifier: Value
        columnName: SHA256
      - identifier: Algorithm
        columnName: Algo_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 'Block' and (Roles has 'Trojan')

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	`Block` transforms: `term`
`Roles`	match	`Trojan` transforms: `term`
`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 Trojan File Hash Indicators with Block Action Rule

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 Trojan File Hash Indicators with Block Action Rule

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`