Clearing of forensic evidence from event logs using wevtutil

Status: available
Severity: high
Time window: 5m
Group by: DeviceId, DeviceName
Source: github.com/Azure/Azure-Sentinel

This query checks for attempts to clear at least 10 log entries from event logs using wevtutil. Clearing event logs can be a sign of ransomware activity, as ransomware often attempts to cover its tracks by deleting logs.

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1070` Indicator Removal

Event coverage

Provider	Event/ActionType	Title
Sysmon	Event ID 1	Process creation
Security-Auditing	Event ID 4688	A new process has been created.
Defender-DeviceProcessEvents	any	Process activity (any)

Rule body kusto

id: 515d0bba-b297-4f83-8280-20ff7f27ecb1
name: Clearing of forensic evidence from event logs using wevtutil
description: |
  This query checks for attempts to clear at least 10 log entries from event logs using wevtutil. Clearing event logs can be a sign of ransomware activity, as ransomware often attempts to cover its tracks by deleting logs.
severity: High
status: Available
requiredDataConnectors:
  - connectorId: MicrosoftThreatProtection
    dataTypes:
      - DeviceProcessEvents
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - DefenseEvasion
relevantTechniques:
  - T1070
query: |
  // Look for use of wevtutil to clear multiple logs
  DeviceProcessEvents
  | where ProcessCommandLine has "WEVTUTIL" and ProcessCommandLine has "CL"
  | summarize LogClearCount = dcount(tostring(ProcessCommandLine)), ClearedLogList = make_set(ProcessCommandLine, 100000) by DeviceId, DeviceName, bin(TimeGenerated, 5m)
  | where LogClearCount > 10
  | extend HostName = iff(DeviceName has '.', substring(DeviceName, 0, indexof(DeviceName, '.')), DeviceName)
  | extend DnsDomain = iff(DeviceName has '.', substring(DeviceName, indexof(DeviceName, '.') + 1), "")
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: DeviceName
      - identifier: HostName
        columnName: HostName
      - identifier: DnsDomain
        columnName: DnsDomain
version: 1.0.0
kind: Scheduled

Stages and Predicates

Stage 1: `source`

DeviceProcessEvents

Stage 2: `where`

| where ProcessCommandLine has "WEVTUTIL" and ProcessCommandLine has "CL"

Stage 3: `summarize`

| summarize LogClearCount = dcount(tostring(ProcessCommandLine)), ClearedLogList = make_set(ProcessCommandLine, 100000) by DeviceId, DeviceName, bin(TimeGenerated, 5m)

Threshold: gt 10

Stage 4: `where`

| where LogClearCount > 10

Stage 5: `extend`

| extend HostName = iff(DeviceName has '.', substring(DeviceName, 0, indexof(DeviceName, '.')), DeviceName)

HostName =

ifDeviceName has "."substring(DeviceName, 0, indexof(DeviceName, '.'))

elseDeviceName

Stage 6: `extend`

| extend DnsDomain = iff(DeviceName has '.', substring(DeviceName, indexof(DeviceName, '.') + 1), "")

DnsDomain =

ifDeviceName has "."substring(DeviceName, (indexof(DeviceName, '.') + 1))

else""

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
`LogClearCount`	gt	`10` transforms: `cased`
`ProcessCommandLine`	match	`CL` transforms: `term` corpus 3 (sigma 2, kusto 1) `WEVTUTIL` transforms: `term`

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
`ClearedLogList`	`summarize`
`DeviceId`	`summarize`
`DeviceName`	`summarize`
`LogClearCount`	`summarize`
`HostName`	`extend`
`DnsDomain`	`extend`

`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)

Clearing of forensic evidence from event logs using wevtutil

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Stage 1: `source`

Stage 2: `where`

Stage 3: `summarize`

Stage 4: `where`

Stage 5: `extend`

Stage 6: `extend`

Indicators

Output fields

Keyboard shortcuts

Search operators

Clearing of forensic evidence from event logs using wevtutil

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: summarize

Stage 4: where

Stage 5: extend

Stage 6: extend

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `summarize`

Stage 4: `where`

Stage 5: `extend`

Stage 6: `extend`