Wab/Wabmig Unusual Parent Or Child Processes

Status: test
Severity: high
Log source: category process_creation, product windows
Author: Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects unusual parent or children of the wab.exe (Windows Contacts) and Wabmig.exe (Microsoft Address Book Import Tool) processes as seen being used with bumblebee activity

MITRE ATT&CK coverage

Tactic	Techniques
Execution	No specific technique
Stealth	No specific technique

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation
Security-Auditing	Event ID 4688: A new process has been created.

Rule body

title: Wab/Wabmig Unusual Parent Or Child Processes
id: 63d1ccc0-2a43-4f4b-9289-361b308991ff
status: test
description: Detects unusual parent or children of the wab.exe (Windows Contacts) and Wabmig.exe (Microsoft Address Book Import Tool) processes as seen being used with bumblebee activity
references:
    - https://thedfirreport.com/2022/08/08/bumblebee-roasts-its-way-to-domain-admin/
    - https://symantec-enterprise-blogs.security.com/blogs/threat-intelligence/bumblebee-loader-cybercrime
    - https://thedfirreport.com/2022/09/26/bumblebee-round-two/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-08-12
modified: 2022-09-27
tags:
    - attack.execution
    - attack.stealth
logsource:
    category: process_creation
    product: windows
detection:
    selection_parent:
        ParentImage|endswith:
            # Add more if known
            - \WmiPrvSE.exe
            - \svchost.exe
            - \dllhost.exe
        Image|endswith:
            - '\wab.exe'
            - '\wabmig.exe' # (Microsoft Address Book Import Tool)
    selection_child:
        # You can add specific suspicious child processes (such as cmd, powershell...) to increase the accuracy
        ParentImage|endswith:
            - '\wab.exe'
            - '\wabmig.exe' # (Microsoft Address Book Import Tool)
    condition: 1 of selection_*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: `condition`

1 of selection_*

Stage 1: `selection_parent`

selection_parent:
    ParentImage|endswith:
        - \WmiPrvSE.exe
        - \svchost.exe
        - \dllhost.exe
    Image|endswith:
        - '\wab.exe'
        - '\wabmig.exe'

Stage 2: `selection_child`

selection_child:
    ParentImage|endswith:
        - '\wab.exe'
        - '\wabmig.exe'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Image`	ends_with	`\wab.exe` corpus 2 (sigma 2) `\wabmig.exe` corpus 2 (sigma 2)	`field:"Image" kind:ends_with`
`ParentImage`	ends_with	`\WmiPrvSE.exe` corpus 8 (sigma 8) `\dllhost.exe` corpus 7 (sigma 7) `\svchost.exe` corpus 15 (sigma 14, kusto 1) `\wab.exe` `\wabmig.exe`	`field:"ParentImage" kind:ends_with`