Detection rules › Kusto
Potential re-named sdelete usage (ASIM Version)
This detection looks for command line parameters associated with the use of Sysinternals sdelete (https://docs.microsoft.com/sysinternals/downloads/sdelete) to delete multiple files on a host's C drive. A threat actor may re-name the tool to avoid detection and then use it for destructive attacks on a host. This detection uses the ASIM imProcess parser, this will need to be deployed before use - https://docs.microsoft.com/azure/sentinel/normalization
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | T1036 Masquerading |
| Impact | T1485 Data Destruction |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Sysmon | Event ID 5 | Process terminated |
| Security-Auditing | Event ID 4688 | A new process has been created. |
| Security-Auditing | Event ID 4689 | A process has exited. |
Rule body kusto
id: 5b6ae038-f66e-4f74-9315-df52fd492be4
name: Potential re-named sdelete usage (ASIM Version)
description: |
'This detection looks for command line parameters associated with the use of Sysinternals sdelete (https://docs.microsoft.com/sysinternals/downloads/sdelete) to delete multiple files on a host's C drive.
A threat actor may re-name the tool to avoid detection and then use it for destructive attacks on a host.
This detection uses the ASIM imProcess parser, this will need to be deployed before use - https://docs.microsoft.com/azure/sentinel/normalization'
severity: Low
requiredDataConnectors: []
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- DefenseEvasion
- Impact
relevantTechniques:
- T1485
- T1036
query: |
imProcess
| where CommandLine has_all ("accepteula", "-s", "-r", "-q")
| where Process !endswith "sdelete.exe"
| where CommandLine !has "sdelete"
| extend AccountName = tostring(split(ActorUsername, @'\')[1]), AccountNTDomain = tostring(split(ActorUsername, @'\')[0])
entityMappings:
- entityType: Account
fieldMappings:
- identifier: FullName
columnName: ActorUsername
- identifier: Name
columnName: AccountName
- identifier: NTDomain
columnName: AccountNTDomain
- entityType: Host
fieldMappings:
- identifier: FullName
columnName: Dvc
- identifier: HostName
columnName: DvcHostname
- identifier: DnsDomain
columnName: DvcDomain
- entityType: IP
fieldMappings:
- identifier: Address
columnName: DvcIpAddr
version: 1.0.6
kind: Scheduled
metadata:
source:
kind: Community
author:
name: Microsoft Security Research
support:
tier: Community
categories:
domains: [ "Security - Threat Protection" ]
Stages and Predicates
Stage 1: source
imProcess
Stage 2: where
| where CommandLine has_all ("accepteula", "-s", "-r", "-q")
Stage 3: where
| where Process !endswith "sdelete.exe"
Stage 4: where
| where CommandLine !has "sdelete"
Stage 5: extend
| extend AccountName = tostring(split(ActorUsername, @'\')[1]), AccountNTDomain = tostring(split(ActorUsername, @'\')[0])
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
Process | ends_with | sdelete.exe |
CommandLine | match | sdelete |
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 |
|---|---|---|
CommandLine | match |
|
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 |
|---|---|
AccountNTDomain | extend |
AccountName | extend |