Hub configuration

Name: PowerShell Base64 Encoded FromBase64String Cmdlet
Author: sigmahq

More info

PowerShell Base64 Encoded FromBase64String Cmdlet Detection Scenario by sigmahq | CrowdSec Hub

« PowerShell Base64 Encoded FromBase64String Cmdlet »
v0.2 by sigmahq / proc_creation_win_powershell_base64_frombase64string
Attack scenariowindowsNot spoofableLow confidence

Detects usage of a base64 encoded "FromBase64String" cmdlet in a process command line

Installation

cscli scenarios install sigmahq/proc_creation_win_powershell_base64_frombase64string

YAML Configuration

1type: trigger
2name: sigmahq/proc_creation_win_powershell_base64_frombase64string
3description: |
4  Detects usage of a base64 encoded "FromBase64String" cmdlet in a process command line
5filter: |
6  (evt.Meta.service == 'sysmon' && evt.Parsed.EventID == '1') && (evt.Parsed.CommandLine contains 'OjpGcm9tQmFzZTY0U3RyaW5n' || evt.Parsed.CommandLine contains 'o6RnJvbUJhc2U2NFN0cmluZ' || evt.Parsed.CommandLine contains '6OkZyb21CYXNlNjRTdHJpbm' || evt.Parsed.CommandLine contains 'OgA6AEYAcgBvAG0AQgBhAHMAZQA2ADQAUwB0AHIAaQBuAGcA' || evt.Parsed.CommandLine contains 'oAOgBGAHIAbwBtAEIAYQBzAGUANgA0AFMAdAByAGkAbgBnA' || evt.Parsed.CommandLine contains '6ADoARgByAG8AbQBCAGEAcwBlADYANABTAHQAcgBpAG4AZw')
7blackhole: 2m
8#status: test
9labels:
10  service: windows
11  confidence: 1
12  spoofable: 0
13  classification:
14   - attack.t1140
15   - attack.t1059.001
16
17  label: "PowerShell Base64 Encoded FromBase64String Cmdlet"
18  behavior : "windows:audit"
19  remediation: false
20
21scope:
22  type: ParentProcessId
23  expression: evt.Parsed.ParentProcessId
24
25

Hub configuration

« PowerShell Base64 Encoded FromBase64String Cmdlet »v0.2 by sigmahq / proc_creation_win_powershell_base64_frombase64stringAttack scenariowindowsNot spoofableLow confidenceMITRE:t1140MITRE:t1059

« PowerShell Base64 Encoded FromBase64String Cmdlet »
v0.2 by sigmahq / proc_creation_win_powershell_base64_frombase64string
Attack scenariowindowsNot spoofableLow confidence