Sigma rule: IIS WebServer Log Deletion via CommandLine Utilities

Rule

Title

IIS WebServer Log Deletion via CommandLine Utilities

Status

experimental

Level

medium

Author

Swachchhanda Shrawan Poudel (Nextron Systems)

Date

2025-09-02

File

rules/windows/process_creation/proc_creation_win_iis_logs_deletion.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects attempts to delete Internet Information Services (IIS) log files via command line utilities, which is a common defense evasion technique used by attackers to cover their tracks.
Threat actors often abuse vulnerabilities in web applications hosted on IIS servers to gain initial access and later delete IIS logs to evade detection.

Log source

product

windows

category

process_creation

Detection

selection_img:
    - Image|endswith:
          - '\cmd.exe'
          - '\powershell_ise.exe'
          - '\powershell.exe'
          - '\pwsh.exe'
    - OriginalFileName:
          - 'cmd.exe'
          - 'powershell.exe'
          - 'powershell_ise.exe'
          - 'pwsh.dll'
selection_cli_del:
    CommandLine|contains:
        - 'del '
        - 'erase '
        - 'rm '
        - 'remove-item '
        - 'rmdir '
selection_cli_iis_dir:
    CommandLine|contains: '\inetpub\logs\'
condition: all of selection_*

False positives (as the rule lists them)

• Deletion of IIS logs that are older than a certain retention period as part of regular maintenance activities.
• Legitimate schedule tasks or scripts that clean up log files regularly.

Tags

• attack.stealth
• attack.t1070

MITRE ATT&CK ids this rule names

• T1070

Related rules

• 3eb8c339-a765-48cc-a150-4364c04652bf (similar)

References

• https://learn.microsoft.com/en-us/iis/manage/provisioning-and-managing-iis/managing-iis-log-file-storage

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_iis_logs_deletion.yml