Slack Legal Hold Policy Modified

Severity: high
Log types: Slack.AuditLogs
Tags: Slack, Defense Evasion, Impair Defenses, Disable or Modify Tools
Reference: https://slack.com/intl/en-gb/help/articles/4401830811795-Create-and-manage-legal-holds
Source: github.com/panther-labs/panther-analysis

Detects changes to configured legal hold policies

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1562.001` Impair Defenses: Disable or Modify Tools

Rule body yaml

AnalysisType: rule
Filename: slack_legal_hold_policy_modified.py
RuleID: "Slack.AuditLogs.LegalHoldPolicyModified"
DisplayName: "Slack Legal Hold Policy Modified"
Enabled: true
LogTypes:
  - Slack.AuditLogs
Tags:
  - Slack
  - Defense Evasion
  - Impair Defenses
  - Disable or Modify Tools
Reports:
  MITRE ATT&CK:
    - TA0005:T1562.001
Severity: High
Description: Detects changes to configured legal hold policies
Reference: https://slack.com/intl/en-gb/help/articles/4401830811795-Create-and-manage-legal-holds
DedupPeriodMinutes: 60
Threshold: 1
SummaryAttributes:
  - p_any_ip_addresses
  - p_any_emails
Tests:
  - Name: Legal Hold - Entities Deleted
    ExpectedResult: true
    Log:
      {
        "action": "legal_hold_policy_entities_deleted",
        "actor":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "A012B3CDEFG",
                "name": "username",
                "team": "T01234N56GB",
              },
          },
        "context":
          {
            "ip_address": "1.2.3.4",
            "location":
              {
                "domain": "test-workspace",
                "id": "T01234N56GB",
                "name": "test-workspace",
                "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: Legal Hold - Exclusions Added
    ExpectedResult: true
    Log:
      {
        "action": "legal_hold_policy_exclusion_added",
        "actor":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "A012B3CDEFG",
                "name": "username",
                "team": "T01234N56GB",
              },
          },
        "context":
          {
            "ip_address": "1.2.3.4",
            "location":
              {
                "domain": "test-workspace",
                "id": "T01234N56GB",
                "name": "test-workspace",
                "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: Legal Hold - Policy Released
    ExpectedResult: true
    Log:
      {
        "action": "legal_hold_policy_released",
        "actor":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "A012B3CDEFG",
                "name": "username",
                "team": "T01234N56GB",
              },
          },
        "context":
          {
            "ip_address": "1.2.3.4",
            "location":
              {
                "domain": "test-workspace",
                "id": "T01234N56GB",
                "name": "test-workspace",
                "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: Legal Hold - Policy Updated
    ExpectedResult: true
    Log:
      {
        "action": "legal_hold_policy_updated",
        "actor":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "A012B3CDEFG",
                "name": "username",
                "team": "T01234N56GB",
              },
          },
        "context":
          {
            "ip_address": "1.2.3.4",
            "location":
              {
                "domain": "test-workspace",
                "id": "T01234N56GB",
                "name": "test-workspace",
                "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",
      }

Detection logic

Condition

action in ["legal_hold_policy_entities_deleted", "legal_hold_policy_exclusion_added", "legal_hold_policy_released", "legal_hold_policy_updated"]

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`	in	`legal_hold_policy_entities_deleted` `legal_hold_policy_exclusion_added` `legal_hold_policy_released` `legal_hold_policy_updated`

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`
`name`	`details.old_legal_hold_policy.name`
`action`

`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)