File Deletion Via Del

SIGMA detection rule by frack113 · NOASSERTION

Detects execution of the builtin "del"/"erase" commands in order to delete files. Adversaries may delete files left behind by the actions of their intrusion activity. Malware, tools, or other non-native files dropped or created on a system by an adversary may leave traces to indicate to what was done within a network and how. Removal of these files can occur during an intrusion, or as part of a post-intrusion process to minimize the adversary's footprint.

title: File Deletion Via Del
id: 379fa130-190e-4c3f-b7bc-6c8e834485f3
status: test
description: |
    Detects execution of the builtin "del"/"erase" commands in order to delete files.
    Adversaries may delete files left behind by the actions of their intrusion activity.
    Malware, tools, or other non-native files dropped or created on a system by an adversary may leave traces to indicate to what was done within a network and how.
    Removal of these files can occur during an intrusion, or as part of a post-intrusion process to minimize the adversary's footprint.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1070.004/T1070.004.md
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/erase
author: frack113
date: 2022-01-15
modified: 2024-03-05
tags:
    - attack.stealth
    - attack.t1070.004
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\cmd.exe'
        - OriginalFileName: 'Cmd.Exe'
    selection_del:
        CommandLine|contains:
            - 'del '
            - 'erase '
    selection_flags:
        CommandLine|contains|windash:
            - ' -f' # Force deleting of read-only files.
            - ' -s' # Delete specified files from all subdirectories.
            - ' -q' # Quiet mode, do not ask if ok to delete on global wildcard
    condition: all of selection_*
falsepositives:
    - False positives levels will differ Depending on the environment. You can use a combination of ParentImage and other keywords from the CommandLine field to filter legitimate activity
level: low

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Executable code, not a declarative rule

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