File Deleted Via Sysinternals SDelete

Status: test
Severity: medium
Log source: category file_delete, product windows
Author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)
Source: github.com/SigmaHQ/sigma

Detects the deletion of files by the Sysinternals SDelete utility. It looks for the common name pattern used to rename files.

Known false positives

Legitimate usage

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1070.004` Indicator Removal: File Deletion

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 23: FileDelete (File Delete archived)
Sysmon	Event ID 26: FileDeleteDetected (File Delete logged)

Rule body

title: File Deleted Via Sysinternals SDelete
id: 6ddab845-b1b8-49c2-bbf7-1a11967f64bc
status: test
description: Detects the deletion of files by the Sysinternals SDelete utility. It looks for the common name pattern used to rename files.
references:
    - https://github.com/OTRF/detection-hackathon-apt29/issues/9
    - https://github.com/OTRF/ThreatHunter-Playbook/blob/2d4257f630f4c9770f78d0c1df059f891ffc3fec/docs/evals/apt29/detections/4.B.4_83D62033-105A-4A02-8B75-DAB52D8D51EC.md
author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)
date: 2020-05-02
modified: 2023-02-15
tags:
    - attack.stealth
    - attack.t1070.004
logsource:
    product: windows
    category: file_delete
detection:
    selection:
        TargetFilename|endswith:
            - '.AAA'
            - '.ZZZ'
    filter_wireshark:
        TargetFilename|endswith: '\Wireshark\radius\dictionary.alcatel-lucent.aaa'
    condition: selection and not 1 of filter_*
falsepositives:
    - Legitimate usage
level: medium

Stages and Predicates

Stage 0: `condition`

selection and not 1 of filter_*

Stage 1: `selection`

selection:
    TargetFilename|endswith:
        - '.AAA'
        - '.ZZZ'

Stage 2: `not filter_wireshark`

filter_wireshark:
    TargetFilename|endswith: '\Wireshark\radius\dictionary.alcatel-lucent.aaa'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`TargetFilename`	ends_with	`\Wireshark\radius\dictionary.alcatel-lucent.aaa`	`excludes:TargetFilename` `field:"TargetFilename" value:"\Wireshark\radius\dictionary.alcatel-lucent.aaa"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`TargetFilename`	ends_with	`.AAA` `.ZZZ`	`field:"TargetFilename" kind:ends_with`