Threat Huntmediumtest
Potential Data Exfiltration Via Curl.EXE
Detects the execution of the "curl" process with "upload" flags. Which might indicate potential data exfiltration
Convert In Phoenix Studio
Open this Sigma rule in the converter with the YAML preloaded and ready for backend selection.
Launch
Florian Roth (Nextron Systems), Cedric MAURUGEONCreated Fri Jul 03Updated Tue May 0200bca14a-df4e-4649-9054-3f2aa676bc04windows
Hunting Hypothesis
Log Source
WindowsProcess Creation
ProductWindows← raw: windows
CategoryProcess Creation← raw: process_creation
Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.
Detection Logic
Detection Logic3 selectors
detection:
selection_img:
- Image|endswith: '\curl.exe'
- Product: 'The curl executable'
selection_cli:
- CommandLine|contains:
- ' --form' # Also covers the "--form-string"
- ' --upload-file '
- ' --data '
- ' --data-' # For flags like: "--data-ascii", "--data-binary", "--data-raw", "--data-urlencode"
- CommandLine|re: '\s-[FTd]\s' # We use regex to ensure a case sensitive argument detection
filter_optional_localhost:
CommandLine|contains:
- '://localhost'
- '://127.0.0.1'
condition: all of selection_* and not 1 of filter_optional_*False Positives
Scripts created by developers and admins
MITRE ATT&CK
Other
detection.threat-hunting
Rule Metadata
Rule ID
00bca14a-df4e-4649-9054-3f2aa676bc04
Status
test
Level
medium
Type
Threat Hunt
Created
Fri Jul 03
Modified
Tue May 02
Path
rules-threat-hunting/windows/process_creation/proc_creation_win_curl_fileupload.yml
Raw Tags
attack.exfiltrationattack.command-and-controlattack.t1567attack.t1105detection.threat-hunting