Sigma rule: Suspicious File Download From IP Via Curl.EXE

Rule

Title

Suspicious File Download From IP Via Curl.EXE

Status

test

Level

high

Author

Nasreddine Bencherchali (Nextron Systems)

Date

2023-07-27

File

rules/windows/process_creation/proc_creation_win_curl_download_direct_ip_susp_extensions.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects potentially suspicious file downloads directly from IP addresses using curl.exe

Log source

product

windows

category

process_creation

Detection

selection_img:
    - Image|endswith: '\curl.exe'
    - OriginalFileName: 'curl.exe'
selection_ip:
    CommandLine|re: '://[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'
selection_http:
    CommandLine|contains: 'http'
selection_flag:
    CommandLine|contains:
        - ' -O'  # covers the alias for --remote-name and --output
        - '--remote-name'
        - '--output'
selection_ext:
    # Note: If you add more extensions please consider adding them also in 9cc85849-3b02-4cb5-b371-3a1ff54f2218
    CommandLine|endswith:
        - '.bat'
        - '.bat"'
        - '.dat'
        - '.dat"'
        - '.dll'
        - '.dll"'
        - '.exe'
        - '.exe"'
        - '.gif'
        - '.gif"'
        - '.hta'
        - '.hta"'
        - '.jpeg'
        - '.jpeg"'
        - '.log'
        - '.log"'
        - '.msi'
        - '.msi"'
        - '.png'
        - '.png"'
        - '.ps1'
        - '.ps1"'
        - '.psm1'
        - '.psm1"'
        - '.vbe'
        - '.vbe"'
        - '.vbs'
        - '.vbs"'
        - ".bat'"
        - ".dat'"
        - ".dll'"
        - ".exe'"
        - ".gif'"
        - ".hta'"
        - ".jpeg'"
        - ".log'"
        - ".msi'"
        - ".png'"
        - ".ps1'"
        - ".psm1'"
        - ".vbe'"
        - ".vbs'"
condition: all of selection_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.execution

References

• https://labs.withsecure.com/publications/fin7-target-veeam-servers
• https://github.com/WithSecureLabs/iocs/blob/344203de742bb7e68bd56618f66d34be95a9f9fc/FIN7VEEAM/iocs.csv
• https://github.com/pr0xylife/IcedID/blob/8dd1e218460db4f750d955b4c65b2f918a1db906/icedID_09.28.2023.txt

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_curl_download_direct_ip_susp_extensions.yml