Netskope Many Objects Deleted

Severity: high
Log types: Netskope.Audit
Tags: Netskope, Configuration Required, Data Destruction
Reference: https://docs.netskope.com/en/netskope-help/admin-console/administration/audit-log/
Source: github.com/panther-labs/panther-analysis

A user deleted a large number of objects in a short period of time.

MITRE ATT&CK coverage

Tactic	Techniques
Impact	`T1485` Data Destruction

Rule body yaml

AnalysisType: rule
RuleID: "Netskope.ManyDeletes"
DisplayName: "Netskope Many Objects Deleted"
Enabled: true
Filename: netskope_many_deletes.py
LogTypes:
  - Netskope.Audit
Tags:
  - Netskope
  - Configuration Required # configure threshold for your environment
  - Data Destruction
Reports:
  MITRE ATT&CK:
    - TA0040:T1485
Severity: High
Description: A user deleted a large number of objects in a short period of time.
DedupPeriodMinutes: 60
Threshold: 10
Runbook: A user deleted a large number of objects in a short period of time.  Validate that this activity is expected and authorized.
Reference: https://docs.netskope.com/en/netskope-help/admin-console/administration/audit-log/
Tests:
  - Name: True positive
    ExpectedResult: true
    Log:
      {
        "_id": "1e589befa3da30132362f32a",
        "_insertion_epoch_timestamp": 1702318213,
        "audit_log_event": "Deleted rbi template",
        "count": 1,
        "is_netskope_personnel": false,
        "organization_unit": "",
        "severity_level": 2,
        "timestamp": "2023-12-11 18:10:13.000000000",
        "type": "admin_audit_logs",
        "ur_normalized": "service-account",
        "user": "service-account",
      }
  - Name: True negative
    ExpectedResult: false
    Log:
      {
        "_id": "1e589befa3da30132362f32a",
        "_insertion_epoch_timestamp": 1702318213,
        "audit_log_event": "Rest API V2 Call",
        "count": 1,
        "is_netskope_personnel": false,
        "organization_unit": "",
        "severity_level": 2,
        "supporting_data":
          {
            "data_type": "incidents",
            "data_values":
              [
                200,
                "POST",
                "/api/v2/incidents/uba/getuci",
                "trid=ccb898fgrhvdd0v0lebg",
              ],
          },
        "timestamp": "2023-12-11 18:10:13.000000000",
        "type": "admin_audit_logs",
        "ur_normalized": "service-account",
        "user": "service-account",
      }

Detection logic

Condition

audit_log_event is_not_null
audit_log_event contains "Delete"

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
`audit_log_event`	contains	`Delete`
`audit_log_event`	is_not_null	(no value, null check)

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
`user`

`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)