Linux Curl Upload File
SPLUNK detection rule by Michael Haag, Splunk · Apache-2.0
The following analytic detects the use of the curl command with specific switches (-F, --form, --upload-file, -T, -d, --data, --data-raw, -I, --head) to upload AWS credentials or configuration files to a remote destination. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and process details. This activity is significant as it may indicate an attempt to exfiltrate sensitive AWS credentials, a technique known to be used by the TeamTNT group. If confirmed malicious, this could lead to unauthorized access and potential compromise of AWS resources.
name: Linux Curl Upload File
id: c1de2d9a-0c02-4bb4-a49a-510c6e9cf2bf
version: 13
creation_date: '2022-07-29'
modification_date: '2026-05-13'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic detects the use of the curl command with specific switches (-F, --form, --upload-file, -T, -d, --data, --data-raw, -I, --head) to upload AWS credentials or configuration files to a remote destination. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and process details. This activity is significant as it may indicate an attempt to exfiltrate sensitive AWS credentials, a technique known to be used by the TeamTNT group. If confirmed malicious, this could lead to unauthorized access and potential compromise of AWS resources.
data_source:
- Sysmon for Linux EventID 1
- Cisco Isovalent Process Exec
search: |-
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
WHERE Processes.process_name=curl Processes.process IN ("*-F *", "*--form *","*--upload-file *","*-T *","*-d *","*--data *","*--data-raw *", "*-I *", "*--head *")
AND
Processes.process IN ("*.aws/credentials*". "*.aws/config*")
BY Processes.action Processes.dest Processes.original_file_name
Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
Processes.process Processes.process_exec Processes.process_guid
Processes.process_hash Processes.process_id Processes.process_integrity_level
Processes.process_name Processes.process_path Processes.user
Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `linux_curl_upload_file_filter`
how_to_implement: The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives: Filtering may be required. In addition to AWS credentials, add other important files and monitor. The inverse would be to look for _all_ -F behavior and tune from there.
references:
- https://curl.se/docs/manpage.html
- https://www.cadosecurity.com/team-tnt-the-first-crypto-mining-worm-to-steal-aws-credentials/
- https://gtfobins.github.io/gtfobins/curl/
drilldown_searches:
- name: View the detection results for - "$user$" and "$dest$"
search: '%original_detection_search% | search user = "$user$" dest = "$dest$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$user$" and "$dest$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset: 7d
latest_offset: "0"
finding:
title: An instance of $process_name$ was identified on endpoint $dest$ by user $user$ attempting to upload important files to a remote destination.
entity:
field: user
type: user
score: 50
intermediate_findings:
entities:
- field: dest
type: system
score: 50
message: An instance of $process_name$ was identified on endpoint $dest$ by user $user$ attempting to upload important files to a remote destination.
threat_objects:
- field: process_name
type: process_name
analytic_story:
- Linux Living Off The Land
- Data Exfiltration
- Ingress Tool Transfer
- NPM Supply Chain Compromise
asset_type: Endpoint
mitre_attack_id:
- T1105
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1105/atomic_red_team/curl-linux-sysmon.log
source: Syslog:Linux-Sysmon/Operational
sourcetype: sysmon:linux
test_type: unit
- name: True Positive Test - Cisco Isovalent
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/cisco_isovalent/cisco_isovalent.log
source: not_applicable
sourcetype: cisco:isovalent:processExec
test_type: unit
CIRCL