ZIA Logs Downloaded

Severity: medium
Log types: Zscaler.ZIA.AdminAuditLog
Reference: https://help.zscaler.com/zia/about-audit-logs
Source: github.com/panther-labs/panther-analysis

This rule detects when ZIA Audit Logs were downloaded.

MITRE ATT&CK coverage

Tactic	Techniques
Discovery	`T1654` Log Enumeration

Rule body yaml

AnalysisType: rule
RuleID: ZIA.Logs.Downloaded
Description: This rule detects when ZIA Audit Logs were downloaded.
DisplayName: ZIA Logs Downloaded
Runbook: Verify that this change was planned. If not, make sure no sensitive information was leaked.
Reference: https://help.zscaler.com/zia/about-audit-logs
Enabled: true
Filename: zia_logs_downloaded.py
Severity: Medium
Reports:
  MITRE ATT&CK:
    - TA0007:T1654 # Log Enumeration
LogTypes:
  - Zscaler.ZIA.AdminAuditLog
DedupPeriodMinutes: 60
Threshold: 1
Tests:
  - Name: Logs downloaded
    ExpectedResult: true
    Log:
      {
        "event": {
          "action": "DOWNLOAD",
          "adminid": "admin@test.zscalerbeta.net",
          "auditlogtype": "ZIA",
          "category": "AUDIT_LOGS",
          "clientip": "1.2.3.4",
          "errorcode": "None",
          "interface": "UI",
          "postaction": { },
          "preaction": { },
          "recordid": "363",
          "resource": "None",
          "result": "SUCCESS",
          "subcategory": "AUDIT_LOGS",
          "time": "2024-11-04 16:31:24.000000000"
        },
        "sourcetype": "zscalernss-audit"
      }
  - Name: Other event
    ExpectedResult: false
    Log:
      {
        "event": {
          "action": "SIGN_IN",
          "adminid": "admin@test.zscalerbeta.net",
          "auditlogtype": "ZIA",
          "category": "LOGIN",
          "clientip": "1.2.3.4",
          "errorcode": "None",
          "interface": "UI",
          "postaction": { },
          "preaction": { },
          "recordid": "354",
          "resource": "None",
          "result": "SUCCESS",
          "subcategory": "LOGIN",
          "time": "2024-11-04 16:27:37.000000000"
        },
        "sourcetype": "zscalernss-audit"
      }

Detection logic

Condition

event.errorcode eq "None"
event.result eq "SUCCESS"
event.action eq "DOWNLOAD"
event.category eq "AUDIT_LOGS"

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
`event.action`	eq	`DOWNLOAD`
`event.category`	eq	`AUDIT_LOGS`
`event.errorcode`	eq	`None`
`event.result`	eq	`SUCCESS`

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
`action`	`event.action`
`admin_id`	`event.adminid`
`category`	`event.category`
`client_ip`	`event.clientip`
`preaction`	`event.preaction`
`postaction`	`event.postaction`

`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)