Sigma rule: Suspicious Invoke-WebRequest Execution

Rule

Title

Suspicious Invoke-WebRequest Execution

Status

test

Level

high

Author

Nasreddine Bencherchali (Nextron Systems)

Date

2022-08-02

Modified

2025-07-18

File

rules/windows/process_creation/proc_creation_win_powershell_invoke_webrequest_download.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects a suspicious call to Invoke-WebRequest cmdlet where the and output is located in a suspicious location

Log source

product

windows

category

process_creation

Detection

selection_img:
    - Image|endswith:
          - '\powershell_ise.exe'
          - '\powershell.exe'
          - '\pwsh.exe'
    - OriginalFileName:
          - 'powershell_ise.EXE'
          - 'PowerShell.EXE'
          - 'pwsh.dll'
selection_commands:
    CommandLine|contains:
        # These are all aliases of Invoke-WebRequest
        - 'curl '
        - 'Invoke-WebRequest'
        - 'iwr '
        - 'wget '
selection_flags:
    CommandLine|contains:
        - ' -ur'
        - ' -o'
selection_susp_locations:
    CommandLine|contains:
        - '\AppData\'
        - '\Desktop\'
        - '\Temp\'
        - '\Users\Public\'
        - '%AppData%'
        - '%Public%'
        - '%Temp%'
        - '%tmp%'
        - ':\Windows\'
condition: all of selection_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.command-and-control
• attack.t1105

MITRE ATT&CK ids this rule names

• T1105

Related rules

• e218595b-bbe7-4ee5-8a96-f32a24ad3468 (derived)

References

• https://www.sentinelone.com/blog/living-off-windows-defender-lockbit-ransomware-sideloads-cobalt-strike-through-microsoft-security-tool/

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_powershell_invoke_webrequest_download.yml