Detection rules › Sigma
File Download From IP Based URL Via CertOC.EXE
Detects when a user downloads a file from an IP based URL using CertOC.exe
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
Rule body
title: File Download From IP Based URL Via CertOC.EXE
id: b86f6dea-0b2f-41f5-bdcc-a057bd19cd6a
related:
- id: 70ad0861-d1fe-491c-a45f-fa48148a300d
type: similar
status: test
description: Detects when a user downloads a file from an IP based URL using CertOC.exe
references:
- https://lolbas-project.github.io/lolbas/Binaries/Certoc/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-10-18
tags:
- attack.command-and-control
- attack.execution
- attack.t1105
logsource:
category: process_creation
product: windows
detection:
selection_img:
- Image|endswith: '\certoc.exe'
- OriginalFileName: 'CertOC.exe'
selection_ip:
CommandLine|re: '://[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'
selection_cli:
CommandLine|contains: '-GetCACAPS'
condition: all of selection*
falsepositives:
- Unknown
level: high
Stages and Predicates
Stage 0: condition
all of selection*Stage 1: selection_img
selection_img:
- Image|endswith: '\certoc.exe'
- OriginalFileName: 'CertOC.exe'
Stage 2: selection_ip
selection_ip:
CommandLine|re: '://[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'
Stage 3: selection_cli
selection_cli:
CommandLine|contains: '-GetCACAPS'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | match |
| field:"CommandLine" kind:match value:"-GetCACAPS" |
CommandLine | regex_match |
| field:"CommandLine" kind:regex_match value:"://[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}" |
Image | ends_with |
| field:"Image" kind:ends_with value:"\certoc.exe" |
OriginalFileName | eq |
| field:"OriginalFileName" kind:eq value:"CertOC.exe" |