Detect Exfiltration Over Bluetooth in Elastic Security
Adversaries may attempt to exfiltrate data over Bluetooth rather than the command and control channel. If the command and control network is a wired Internet connection, an adversary may opt to exfiltrate data using a Bluetooth communication channel. Adversaries may choose to do this if they have sufficient access and proximity. Bluetooth connections might not be secured or defended as well as the primary Internet-connected channel because it is not routed through the same enterprise network. Real-world examples include the Flame malware's BeetleJuice module, which transmitted encoded data over Bluetooth and acted as a Bluetooth beacon to identify nearby Bluetooth-enabled devices.
MITRE ATT&CK
- Tactic
- Exfiltration
- Sub-technique
- T1011.001 Exfiltration Over Bluetooth
- Canonical reference
- https://attack.mitre.org/techniques/T1011/001/
Elastic Detection Query
any where
(
event.category == "process" and event.type == "start" and
(
process.name in~ ("btattach", "btmgmt", "hciconfig", "hcitool", "hcidump", "bluetoothctl",
"sdptool", "rfcomm", "obexftp", "obexd", "bluetooth-sendto", "fsquirt.exe") or
process.command_line like~ "*bluetooth*" or
process.command_line like~ "*rfcomm*" or
process.command_line like~ "*obex*" or
process.command_line like~ "*hcitool*" or
process.command_line like~ "*hciconfig*" or
process.command_line like~ "*btmgmt*" or
process.command_line like~ "*bluetoothctl*" or
process.command_line like~ "*bt-adapter*"
)
) or
(
event.category == "registry" and event.type in ("creation", "change") and
(
registry.path like~ "*Bluetooth*" or
registry.path like~ "*BTHPORT*" or
registry.path like~ "*BTHENUM*" or
registry.path like~ "*BthLE*" or
registry.path like~ "*RFCOMM*" or
registry.path like~ "*OBEX*"
)
) or
(
event.category == "file" and event.type == "creation" and
(
file.path like~ "*bluetooth*" or
file.path like~ "*rfcomm*" or
file.path like~ "*obex*" or
file.path like~ "*btooth*" or
file.name like~ "*bluetooth*" or
file.name like~ "*rfcomm*" or
file.name like~ "*obex*"
)
)Detects T1011.001 Exfiltration Over Bluetooth using Elastic Common Schema fields. Covers three vectors: (1) process launch of known Bluetooth management utilities (btattach, btmgmt, hciconfig, hcitool, hcidump, bluetoothctl, sdptool, rfcomm, obexftp, obexd, fsquirt.exe) or Bluetooth-related command-line patterns; (2) registry creation/modification events targeting Bluetooth stack keys (BTHPORT, BTHENUM, BthLE, RFCOMM, OBEX); (3) file creation events with Bluetooth-related path components. Uses case-insensitive wildcard matching via the like~ operator across all three ECS event categories.
Data Sources
Required Tables
False Positives & Tuning
- IT administrators or help desk staff using bluetoothctl, hciconfig, or btmgmt to pair or configure enterprise Bluetooth peripherals such as keyboards, mice, or headsets during routine device provisioning.
- IoT or embedded systems developers running obexftp, sdptool, or rfcomm on development workstations as part of authorized Bluetooth protocol testing for mobile or embedded product development.
- Automated driver installation or MDM provisioning scripts that write to BTHPORT, BTHENUM, or BthLE registry keys when connecting new Bluetooth adapters or accessories to managed endpoints.
- Linux system initialization scripts invoking btmgmt or hciconfig to enumerate or bring up Bluetooth adapters during boot sequences on dual-use workstations.
Other platforms for T1011.001
Testing Methodology
Validate this detection against 5 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Enumerate Bluetooth Devices on Windows
Expected signal: Sysmon Event ID 1: Process Create with Image=powershell.exe and CommandLine containing 'Get-PnpDevice' and 'Bluetooth'. PowerShell ScriptBlock Log Event ID 4104 with the full enumeration command. No registry modification events, but PnpDevice queries may appear in Windows Plug and Play logs.
- Test 2Linux Bluetooth Device Scan with hcitool
Expected signal: Linux auditd: execve syscall for hcitool with arguments 'scan' and 'lescan'. Syslog/daemon.log: bluetoothd activity logs showing scan initiation. If auditd is configured with execve monitoring: type=EXECVE msg= records with a0='hcitool' a1='scan'. Sysmon for Linux Event ID 1 if deployed.
- Test 3Transfer File via OBEX over Bluetooth on Linux
Expected signal: Linux auditd/Sysmon: execve event for obexftp with arguments including '--bluetooth', a MAC address, and '--put' with the file path. File creation event for /tmp/bt_test_exfil.txt. The process will exit with an error but telemetry is generated. Syslog may show bluetoothd connection attempt to the specified MAC address.
- Test 4Python Bluetooth Exfiltration Script Execution (Windows/Linux)
Expected signal: Sysmon Event ID 1: Process Create for python3.exe or python.exe with CommandLine referencing Bluetooth. Child process creation: powershell.exe spawned by python with 'Get-PnpDevice -Class Bluetooth'. Sysmon Event ID 1 for the child powershell.exe. PowerShell ScriptBlock Log Event ID 4104 for the enumeration command.
- Test 5Bluetooth Registry Key Inspection for Paired Devices
Expected signal: Sysmon Event ID 1: Process Create for reg.exe with query arguments targeting BTHPORT. If PowerShell fallback executes: Sysmon Event ID 1 for powershell.exe with BTHPORT in CommandLine. Sysmon Event ID 12 (Registry key access) for HKLM\SYSTEM\CurrentControlSet\Services\BTHPORT\Parameters\Devices. PowerShell ScriptBlock Log Event ID 4104.
References (10)
- https://attack.mitre.org/techniques/T1011/001/
- https://attack.mitre.org/software/S0143/
- https://securelist.com/the-flame-questions-and-answers/34344/
- https://docs.microsoft.com/en-us/windows-hardware/drivers/bluetooth/bluetooth-host-radio-support
- https://www.bluetooth.com/learn-about-bluetooth/tech-overview/
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1011.001/T1011.001.md
- https://learn.microsoft.com/en-us/windows/security/threat-protection/security-policy-settings/interactive-logon-do-not-require-ctrl-alt-del
- https://www.stigviewer.com/stig/windows_10/2021-08-18/finding/V-220843
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-deviceregistryevents-table
- https://www.sans.org/white-papers/bluetooth-security-overview/
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