Slack Anomaly Detected

Severity: low
Log types: Slack.AuditLogs
Tags: Slack, Command and Control, Application Layer Protocol
Reference: https://api.slack.com/admins/audit-logs-anomaly
Source: github.com/panther-labs/panther-analysis

Passthrough for anomalies detected by Slack

MITRE ATT&CK coverage

Tactic	Techniques
Command & Control	`T1071` Application Layer Protocol

Rule body yaml

AnalysisType: rule
Filename: slack_passthrough_anomaly.py
RuleID: "Slack.AuditLogs.PassthroughAnomaly"
DisplayName: "Slack Anomaly Detected"
Enabled: true
LogTypes:
  - Slack.AuditLogs
Severity: Low
Reports:
  MITRE ATT&CK:
    - TA0011:T1071
Description: Passthrough for anomalies detected by Slack
DedupPeriodMinutes: 60
Threshold: 1
Reference: 
  https://api.slack.com/admins/audit-logs-anomaly
SummaryAttributes:
  - p_any_ip_addresses
  - p_any_emails
Tags:
  - Slack
  - Command and Control
  - Application Layer Protocol
Tests:
  - Name: Name
    ExpectedResult: true
    Log:
      {
        "action": "anomaly",
        "actor": {
          "type": "user",
          "user": {
            "email": "user@example.com",
            "id": "W012J3FEWAU",
            "name": "primary-owner",
            "team": "T01234N56GB"
          }
        },
        "context": {
          "ip_address": "1.2.3.4",
          "location": {
            "domain": "test-workspace-1",
            "id": "T01234N56GB",
            "name": "test-workspace-1",
            "type": "workspace"
          },
          "ua": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36"
        }
      }
  - Name: User Logout
    ExpectedResult: false
    Log:
      {
        "action": "user_logout",
        "actor": {
          "type": "user",
          "user": {
            "email": "user@example.com",
            "id": "W012J3FEWAU",
            "name": "primary-owner",
            "team": "T01234N56GB"
          }
        },
        "context": {
          "ip_address": "1.2.3.4",
          "location": {
            "domain": "test-workspace-1",
            "id": "T01234N56GB",
            "name": "test-workspace-1",
            "type": "workspace"
          },
          "ua": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36"
        },
        "date_create": "2022-07-28 15:22:32",
        "entity": {
          "type": "user",
          "user": {
            "email": "user@example.com",
            "id": "W012J3FEWAU",
            "name": "primary-owner",
            "team": "T01234N56GB"
          }
        },
        "id": "72cac009-9eb3-4dde-bac6-ee49a32a1789"
      }
  - Name: Session Fingerprint
    ExpectedResult: true
    Log:
      {
        "action": "anomaly",
        "actor": {
          "type": "user",
          "user": {
            "email": "user@example.com",
            "id": "W012J3FEWAU",
            "name": "primary-owner",
            "team": "T01234N56GB"
          }
        },
        "context": {
          "ip_address": "1.2.3.4",
          "location": {
            "domain": "test-workspace-1",
            "id": "T01234N56GB",
            "name": "test-workspace-1",
            "type": "workspace"
          },
          "ua": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36"
        },
        "date_create": "2024-08-19 13:54:53.000000000",
        "details": {
          "action_timestamp": 1724075641026703,
          "location": "London, UK",
          "previous_ip_address": "",
          "previous_ua": "",
          "reason": [
            "session_fingerprint"
          ]
        },
        "entity": {
          "type": "user",
          "user": {
            "email": "user@example.com",
            "id": "W012J3FEWAU",
            "name": "primary-owner",
            "team": "T01234N56GB"
          }
        },
        "id": "95edcb27-132a-4420-9229-783b38a16b5a",
        "p_event_time": "2024-08-19 13:54:53.000000000",
        "p_log_type": "Slack.AuditLogs"
      }

Detection logic

Condition

action eq "anomaly"

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
`action`	eq	`anomaly`

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
`actor-name`	`actor.user.name`
`actor-email`	`actor.user.email`
`actor-ip`	`context.ip_address`
`user-agent`	`context.ua`

`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)