detection.wiki

Detection rules › Sigma

Potential File Overwrite Via Sysinternals SDelete

Status
test
Severity
high
Log source
category process_creation, product windows
Author
frack113
Source
github.com/SigmaHQ/sigma

Detects the use of SDelete to erase a file not the free space

MITRE ATT&CK coverage

TacticTechniques
Impact

Telemetry coverage

ProviderRecord / event type
SysmonEvent ID 1: Process creation

Rule body

title: Potential File Overwrite Via Sysinternals SDelete
id: a4824fca-976f-4964-b334-0621379e84c4
status: test
description: Detects the use of SDelete to erase a file not the free space
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1485/T1485.md
author: frack113
date: 2021-06-03
modified: 2023-02-28
tags:
    - attack.impact
    - attack.t1485
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        OriginalFileName: sdelete.exe
    filter:
        CommandLine|contains:
            - ' -h'
            - ' -c'
            - ' -z'
            - ' /\?'
    condition: selection and not filter
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection and not filter

Stage 1: selection

selection:
    OriginalFileName: sdelete.exe

Stage 2: not filter

filter:
    CommandLine|contains:
        - ' -h'
        - ' -c'
        - ' -z'
        - ' /\?'

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
CommandLinematch -cexcludes:CommandLine field:"CommandLine" value:" -c"
CommandLinematch -hexcludes:CommandLine field:"CommandLine" value:" -h"
CommandLinematch -zexcludes:CommandLine field:"CommandLine" value:" -z"
CommandLinematch /\?excludes:CommandLine field:"CommandLine" value:" /\?"

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
OriginalFileNameeq
  • sdelete.exe corpus 4 (sigma 2, elastic 1, splunk 1)
field:"OriginalFileName" kind:eq value:"sdelete.exe"