Malicious SSO DNS Lookup

Severity: medium
Entities: domain_names, ip_addresses, trace_ids
Log types: CiscoUmbrella.DNS, Crowdstrike.DNSRequest, Crowdstrike.FDREvent, Suricata.DNS, Zeek.DNS
Tags: Configuration Required
Reference: https://www.cloudns.net/wiki/article/254/#:~:text=A%20DNS%20query%20(also%20known,associated%20with%20a%20domain%20name
Source: github.com/panther-labs/panther-analysis

The rule looks for DNS requests to sites potentially posing as SSO domains.

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1566` Phishing

Rule body yaml

AnalysisType: rule
Filename: malicious_sso_dns_lookup.py
RuleID: "Standard.MaliciousSSODNSLookup"
DedupPeriodMinutes: 1440 # dedup & threshold is high to prevent alert storms from FPs
DisplayName: "Malicious SSO DNS Lookup"
Enabled: false
LogTypes:
  - CiscoUmbrella.DNS
  - Crowdstrike.DNSRequest
  - Crowdstrike.FDREvent
  - Suricata.DNS
  - Zeek.DNS
Severity: Medium
Threshold: 1000 # dedup & threshold is high to prevent alert storms from FPs
Tags:
  - Configuration Required
Reports:
  MITRE ATT&CK:
    - TA0001:T1566
Description: The rule looks for DNS requests to sites potentially posing as SSO domains.
Runbook: Verify if the destination domain is owned by your organization.
Reference: https://www.cloudns.net/wiki/article/254/#:~:text=A%20DNS%20query%20(also%20known,associated%20with%20a%20domain%20name
SummaryAttributes:
  - p_any_ip_addresses
Tests:
  - Name: Known Good SSO Domain
    ExpectedResult: False
    Log:
      {
        "ContextProcessId": "440890253753908704",
        "ContextThreadId": "0",
        "ContextTimeStamp": "2022-08-31 07:03:48.879",
        "DomainName": "company_name_here.okta.com",
        "EffectiveTransmissionClass": 2,
        "Entitlements": "15",
        "RequestType": "1",
        "event_platform": "Mac",
        "event_simpleName": "DnsRequest",
        "name": "DnsRequestMacV2",
        "p_any_domain_names": ["company_name_here.okta.com"],
        "timestamp": "2022-08-31 07:03:49.195",
      }
  - Name: Potentially Malicious SSO Domain
    ExpectedResult: True
    Log:
      {
        "ContextProcessId": "440890253753908704",
        "ContextThreadId": "0",
        "ContextTimeStamp": "2022-08-31 07:03:48.879",
        "DomainName": "company_name_here-okta.com",
        "EffectiveTransmissionClass": 2,
        "Entitlements": "15",
        "RequestType": "1",
        "event_platform": "Mac",
        "event_simpleName": "DnsRequest",
        "name": "DnsRequestMacV2",
        "p_any_domain_names": ["company_name_here-okta.com"],
        "timestamp": "2022-08-31 07:03:49.195",
      }
  - Name: No Domain
    ExpectedResult: False
    Log:
      {
        "ContextProcessId": "440890253753908704",
        "ContextThreadId": "0",
        "ContextTimeStamp": "2022-08-31 07:03:48.879",
        "EffectiveTransmissionClass": 2,
        "Entitlements": "15",
        "RequestType": "1",
        "event_platform": "Mac",
        "event_simpleName": "DnsRequest",
        "name": "DnsRequestMacV2",
        "p_any_domain_names": [],
        "timestamp": "2022-08-31 07:03:49.195",
      }
  - Name: Known good and malicious domain
    ExpectedResult: True
    Log:
      {
        "ContextProcessId": "440890253753908704",
        "ContextThreadId": "0",
        "ContextTimeStamp": "2022-08-31 07:03:48.879",
        "EffectiveTransmissionClass": 2,
        "Entitlements": "15",
        "RequestType": "1",
        "event_platform": "Mac",
        "event_simpleName": "DnsRequest",
        "name": "DnsRequestMacV2",
        "p_any_domain_names":
          ["company_name_here.okta.com", "company_name_here-maokta.com"],
        "timestamp": "2022-08-31 07:03:49.195",
      }
  - Name: Known good and malicious domain with Crowdstrike.FDREvent
    ExpectedResult: True
    Log:
      {
        "event_simpleName": "DnsRequest",
        "name": "DnsRequestMacV1",
        "aid": "00000000000000000000000000000001",
        "aip": "111.111.111.111",
        "cid": "00000000000000000000000000000002",
        "id": "11111111-0000-1111-0000-111111111111",
        "event":
          {
            "aid": "00000000000000000000000000000001",
            "event_simpleName": "DnsRequest",
            "name": "DnsRequestMacV1",
            "aip": "111.111.111.111",
            "cid": "00000000000000000000000000000002",
            "id": "11111111-0000-1111-0000-111111111111",
            "event_platform": "Mac",
            "timestamp": "2021-10-01 00:00:00.000Z",
            "ConfigBuild": "1007.4.0014301.11",
            "ConfigStateHash": "507116305",
            "Entitlements": "15",
            "ContextThreadId": "0",
            "ContextTimeStamp": "2021-10-08 19:55:04.448Z",
            "ContextProcessId": "111111111111111111",
            "EffectiveTransmissionClass": 2,
            "DomainName": "gooddomain.com",
            "RequestType": "1",
          },
        "event_platform": "Mac",
        "fdr_event_type": "DnsRequest",
        "timestamp": "2021-10-01 00:00:00.000Z",
        "ConfigBuild": "1007.4.0014301.11",
        "ConfigStateHash": "507116305",
        "Entitlements": "15",
        "ContextThreadId": "0",
        "ContextTimeStamp": "2021-10-08 19:55:04.448Z",
        "ContextProcessId": "111111111111111111",
        "EffectiveTransmissionClass": 2,
        "RequestType": "1",
        "p_event_time": "2021-10-08 19:55:04.448Z",
        "p_parse_time": "2021-10-08 20:09:41.933Z",
        "p_log_type": "Crowdstrike.FDREvent",
        "p_row_id": "2ed00000000000000000000000000001",
        "p_source_id": "11111111-1111-1111-1111-111111111111",
        "p_source_label": "Crowdstrike",
        "p_any_ip_addresses": ["111.111.111.111"],
        "p_any_domain_names":
          ["company_name_here.okta.com", "company_name_here-maokta.com"],
        "p_any_trace_ids":
          [
            "00000000000000000000000000000001",
            "00000000000000000000000000000002",
          ],
      }
  - Name: non DnsRequest Crowdstrike.FDREvent event
    ExpectedResult: False
    Log:
      {
        "event_simpleName": "something else",
        "event":
          {
            "aid": "00000000000000000000000000000001",
            "event_simpleName": "something else",
            "ContextTimeStamp": "2021-10-08 19:55:04.448Z",
            "ContextProcessId": "111111111111111111",
            "EffectiveTransmissionClass": 2,
            "DomainName": "gooddomain.com",
            "RequestType": "1",
          },
        "event_platform": "Mac",
        "fdr_event_type": "something else",
        "ContextProcessId": "111111111111111111",
        "EffectiveTransmissionClass": 2,
        "RequestType": "1",
        "p_event_time": "2021-10-08 19:55:04.448Z",
        "p_parse_time": "2021-10-08 20:09:41.933Z",
        "p_log_type": "Crowdstrike.FDREvent",
        "p_row_id": "2ed00000000000000000000000000001",
        "p_source_id": "11111111-1111-1111-1111-111111111111",
        "p_source_label": "Crowdstrike",
        "p_any_ip_addresses": ["111.111.111.111"],
        "p_any_domain_names":
          ["company_name_here.okta.com", "company_name_here-maokta.com"],
        "p_any_trace_ids":
          [
            "00000000000000000000000000000001",
            "00000000000000000000000000000002",
          ],
      }

Detection logic

Condition

not (p_log_type eq "Crowdstrike.FDREvent" and fdr_event_type ne "DnsRequest")

This rule also runs imperative logic the parser cannot express as a filter; the conditions above are the structured part it could extract.

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`fdr_event_type`	ne	`DnsRequest`
`p_log_type`	eq	`Crowdstrike.FDREvent`

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
`p_any_domain_names`

`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)