Detection rules › Splunk
Excessive File Deletion In WinDefender Folder
The following analytic detects excessive file deletion events in the Windows Defender folder. It leverages Sysmon EventCodes 23 and 26 to identify processes deleting multiple files within this directory. This behavior is significant as it may indicate an attempt to corrupt or disable Windows Defender, a key security component. If confirmed malicious, this activity could allow an attacker to disable endpoint protection, facilitating further malicious actions without detection.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Impact | T1485 Data Destruction |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 23 | FileDelete (File Delete archived) |
| Sysmon | 26 | FileDeleteDetected (File Delete logged) |
Stages and Predicates
Stage 1: search
search EventCode IN ("23", "26") TargetFilename="*\\ProgramData\\Microsoft\\Windows Defender\\*"
Stage 2: stats
stats BY action, dest, dvc, signature, signature_id, user, user_id, vendor_product
Stage 3: where
where count>=50
Stage 4: search
search
Stage 5: search
search
Stage 6: search
search `macro`
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 |
|---|---|---|
EventCode | in |
|
TargetFilename | eq |
|
count | ge |
|
Neighbors
Often fire together
Rules that target events appearing in the same incident timelines. They pattern-match on adjacent steps of the same TTP, so an alert from one is often paired with alerts from these. Useful for triage context and for assembling chained-detection rules.
Share event IDs (chain-detection candidates)
Rules that observe the same Windows event-ID pairs as this one. If you're authoring a multi-stage / sequence rule that spans these events, these are the existing detections that already cover one or both endpoints.