Detection rules › Splunk

Windows BitLockerToGo with Network Activity

Status
production
Group by
QueryName, QueryResults, QueryStatus, answer, answer_count, dvc, process_guid, process_name, query, query_count, reply_code_id, signature, signature_id, src, user_id, vendor_product
Author
Michael Haag, Nasreddine Bencherchali, Splunk
Source
github.com/splunk/security_content

The following analytic detects suspicious usage of BitLockerToGo.exe, which has been observed being abused by Lumma stealer malware. The malware leverages this legitimate Windows utility to manipulate registry keys, search for cryptocurrency wallets and credentials, and exfiltrate sensitive data. This activity is significant because BitLockerToGo.exe provides functionality for viewing, copying, and writing files as well as modifying registry branches - capabilities that the Lumma stealer exploits for malicious purposes. If confirmed malicious, this could indicate an active data theft campaign targeting cryptocurrency wallets, browser credentials, and password manager archives. The detection focuses on identifying BitLockerToGo.exe execution patterns that deviate from normal system behavior.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 22DNSEvent (DNS query)

Rule body splunk

name: Windows BitLockerToGo with Network Activity
id: 14e3a089-cc23-4f4d-a770-26e44a31fbac
version: 8
creation_date: '2024-11-13'
modification_date: '2026-05-13'
author: Michael Haag, Nasreddine Bencherchali, Splunk
status: production
type: Hunting
description: The following analytic detects suspicious usage of BitLockerToGo.exe, which has been observed being abused by Lumma stealer malware. The malware leverages this legitimate Windows utility to manipulate registry keys, search for cryptocurrency wallets and credentials, and exfiltrate sensitive data. This activity is significant because BitLockerToGo.exe provides functionality for viewing, copying, and writing files as well as modifying registry branches - capabilities that the Lumma stealer exploits for malicious purposes. If confirmed malicious, this could indicate an active data theft campaign targeting cryptocurrency wallets, browser credentials, and password manager archives. The detection focuses on identifying BitLockerToGo.exe execution patterns that deviate from normal system behavior.
data_source:
    - Sysmon EventID 22
search: |-
    `sysmon` EventCode=22 process_name="bitlockertogo.exe"
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY answer answer_count dvc
           process_exec process_guid process_name
           query query_count reply_code_id
           signature signature_id src
           user_id vendor_product QueryName
           QueryResults QueryStatus
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `windows_bitlockertogo_with_network_activity_filter`
how_to_implement: To successfully implement this search, you need to be ingesting logs with the process name and eventcode = 22 dnsquery executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.
known_false_positives: False positives are likely, as BitLockerToGo.exe is a legitimate Windows utility used for managing BitLocker encryption. However, the detection is designed to flag unusual execution patterns that deviate from standard usage. Filtering may be required to reduce false positives, once confirmed - move to TTP.
references:
    - https://any.run/report/5e9ba24639f70787e56f10a241271ae819ef9c573edb22b9eeade7cb40a2df2a/66f16c7b-2cfc-40c5-91cc-f1cbe9743fa3
    - https://securelist.com/fake-captcha-delivers-lumma-amadey/114312/
analytic_story:
    - Lumma Stealer
    - Hellcat Ransomware
asset_type: Endpoint
mitre_attack_id:
    - T1218
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1218/bitlockertogo/bitlockertogo_windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

Stages and Predicates

Stage 1: search

`sysmon` EventCode=22 process_name="bitlockertogo.exe"

Stage 2: stats

| stats count min(_time) as firstTime max(_time) as lastTime
    BY answer answer_count dvc
       process_exec process_guid process_name
       query query_count reply_code_id
       signature signature_id src
       user_id vendor_product QueryName
       QueryResults QueryStatus

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `windows_bitlockertogo_with_network_activity_filter`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
EventCodeeq
  • 22 corpus 16 (splunk 16)
process_nameeq
  • "bitlockertogo.exe" corpus 2 (splunk 2)