Detection rules › Kusto
Corelight - Multiple files sent over HTTP with abnormal requests
'Detects sources sending multiple compressed files greater than 10MBs sent over HTTP in a short amount of time.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Exfiltration |
Rule body
id: 7226d37b-50ee-4e3b-9f80-5b74080d8f2c
name: Corelight - Multiple files sent over HTTP with abnormal requests
description: |
'Detects sources sending multiple compressed files greater than 10MBs sent over HTTP in a short amount of time.'
severity: Medium
status: Available
requiredDataConnectors:
- connectorId: Corelight
dataTypes:
- Corelight_v2_http
- corelight_http
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- Exfiltration
relevantTechniques:
- T1030
query: |
let threshold = 25;
let fl_size_threshold = 10000000;
corelight_http
| where method in~ ('POST', 'PUT')
| where isempty(referrer)
| where tolong(request_body_len) > fl_size_threshold
| summarize count() by uri, id_orig_h, bin(TimeGenerated, 15m)
| where count_ > threshold
entityMappings:
- entityType: IP
fieldMappings:
- identifier: Address
columnName: id_orig_h
version: 2.1.0
kind: Scheduled
Stages and Predicates
Parameters
let threshold = 25;
let fl_size_threshold = 10000000;
Stage 1: source
corelight_http
Stage 2: where
| where method in~ ('POST', 'PUT')
Stage 3: where
| where isempty(referrer)
Stage 4: where
| where tolong(request_body_len) > fl_size_threshold
Stage 5: summarize
| summarize count() by uri, id_orig_h, bin(TimeGenerated, 15m)
Stage 6: where
| where count_ > threshold
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
count_ | gt |
| field:"count_" kind:gt value:"25" |
method | in |
| field:"method" kind:in |
referrer | is_null | field:"referrer" kind:is_null | |
request_body_len | gt |
| field:"request_body_len" kind:gt value:"10000000" |
Output fields
These fields are emitted when the rule matches.
| Field | Source |
|---|---|
id_orig_h | summarize |
uri | summarize |