mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
Gowthamaraj rajendran
94 lines
3.9 KiB
YAML
94 lines
3.9 KiB
YAML
name: Linux Curl Upload File
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id: c1de2d9a-0c02-4bb4-a49a-510c6e9cf2bf
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version: 1
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date: '2022-07-29'
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author: Michael Haag, Splunk
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status: production
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type: TTP
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description: The following analytic identifies curl being utilized with the -F or
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--form, --upload-file, -T, -d, --data, --data-raw, -I and --head switches to upload
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AWS credentials or config to a remote destination. This enables uploading of binary
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files and so forth. To force the 'content' part to be a file, prefix the file name
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with an @ sign. To just get the content part from a file, prefix the file name with
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the symbol <. The difference between @ and < is then that @ makes a file get attached
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in the post as a file upload, while the < makes a text field and just get the contents
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for that text field from a file. This technique was utlized by the TeamTNT group
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to exfiltrate AWS credentials.
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data_source:
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- Sysmon Event ID 1
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search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
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as lastTime from datamodel=Endpoint.Processes where Processes.process_name=curl
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Processes.process IN ("*-F *", "*--form *","*--upload-file *","*-T *","*-d *","*--data
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*","*--data-raw *", "*-I *", "*--head *") AND Processes.process IN ("*.aws/credentials*".
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"*.aws/config*") by Processes.dest Processes.user Processes.parent_process_name
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Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
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| `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
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| `linux_curl_upload_file_filter`'
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how_to_implement: The detection is based on data that originates from Endpoint Detection
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and Response (EDR) agents. These agents are designed to provide security-related
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telemetry from the endpoints where the agent is installed. To implement this search,
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you must ingest logs that contain the process GUID, process name, and parent process.
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Additionally, you must ingest complete command-line executions. These logs must
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be processed using the appropriate Splunk Technology Add-ons that are specific to
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the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint`
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data model. Use the Splunk Common Information Model (CIM) to normalize the field
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names and speed up the data modeling process.
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known_false_positives: Filtering may be required. In addition to AWS credentials,
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add other important files and monitor. The inverse would be to look for _all_ -F
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behavior and tune from there.
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references:
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- https://curl.se/docs/manpage.html
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- https://www.cadosecurity.com/team-tnt-the-first-crypto-mining-worm-to-steal-aws-credentials/
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- https://gtfobins.github.io/gtfobins/curl/
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tags:
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analytic_story:
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- Linux Living Off The Land
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- Data Exfiltration
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- Ingress Tool Transfer
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asset_type: Endpoint
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confidence: 80
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impact: 80
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message: An instance of $process_name$ was identified on endpoint $dest$ by user
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$user$ attempting to upload important files to a remote destination.
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mitre_attack_id:
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- T1105
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observable:
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- name: user
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type: User
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role:
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- Victim
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- name: dest
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type: Hostname
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role:
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- Victim
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- name: process_name
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type: Process
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role:
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- Child Process
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product:
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- Splunk Enterprise
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- Splunk Enterprise Security
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- Splunk Cloud
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required_fields:
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- _time
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- Processes.dest
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- Processes.user
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- Processes.parent_process_name
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- Processes.parent_process
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- Processes.original_file_name
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- Processes.process_name
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- Processes.process
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- Processes.process_id
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- Processes.parent_process_path
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- Processes.process_path
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- Processes.parent_process_id
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risk_score: 64
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security_domain: endpoint
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tests:
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- name: True Positive Test
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attack_data:
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- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1105/atomic_red_team/curl-linux-sysmon.log
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source: Syslog:Linux-Sysmon/Operational
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sourcetype: sysmon_linux
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update_timestamp: true
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