Detect Firmware Corruption in Sumo Logic CSE
Adversaries may overwrite or corrupt the flash memory contents of system BIOS or other firmware in devices attached to a system in order to render them inoperable or unable to boot, thus denying the availability to use the devices and/or the system. Firmware is software that is loaded and executed from non-volatile memory on hardware devices in order to initialize and manage device functionality. These devices may include the motherboard, hard drive, or video cards. Real-world examples include TrickBot's 'Trickboot' module (2020), which can write or erase UEFI/BIOS firmware of a compromised device, and Bad Rabbit ransomware, which installed a modified bootloader to prevent normal boot-up. Firmware corruption often results in permanent hardware denial-of-availability and may be combined with data destruction for maximum impact.
MITRE ATT&CK
- Tactic
- Impact
- Technique
- T1495 Firmware Corruption
- Canonical reference
- https://attack.mitre.org/techniques/T1495/
Sumo Detection Query
_sourceCategory=windows/sysmon OR _sourceCategory=windows/security
| parse field=Message "Image: *" as process_image nodrop
| parse field=Message "CommandLine: *" as command_line nodrop
| parse field=Message "ImageLoaded: *" as image_loaded nodrop
| parse field=Message "ParentImage: *" as parent_image nodrop
| parse field=Message "User: *" as username nodrop
| parse field=Message "Computer: *" as hostname nodrop
| parse field=Message "EventID: *" as event_id nodrop
| where event_id in ("1", "6", "7")
| eval tool_hit = if(matches(toLowerCase(process_image), ".*(\\\\rw\.exe|\\\\rw64\.exe|\\\\rweverything\.exe|\\\\chipsec\.exe|\\\\chipsec_main\.exe|\\\\flashrom\.exe|\\\\fpt\.exe|\\\\fptw\.exe|\\\\fptw64\.exe|\\\\afuwin\.exe|\\\\afuwin64\.exe|\\\\afudos\.exe|\\\\meinfo\.exe|\\\\amidewin\.exe|\\\\h2offt\.exe|\\\\winphlash\.exe|\\\\ubuild\.exe|\\\\ubu\.exe)$"), 1, 0)
| eval write_hit = if(matches(toLowerCase(command_line), ".*(--write|--erase|--flash|spi[._]write|bios.write|uefi.write|flash.write|nvram.write|writespi|flashrom\\s+-w|chipsec_util.spi.write).*"), 1, 0)
| eval driver_hit = if(matches(toLowerCase(image_loaded), ".*(\\\\rw\.sys|\\\\rwdrv\.sys|\\\\winio\.sys|\\\\winio32\.sys|\\\\winio64\.sys|\\\\physmem\.sys|\\\\pmem\.sys|\\\\dbutil_2_3\.sys|\\\\rtcore64\.sys)$"), 1, 0)
| eval uefi_hit = if(matches(toLowerCase(process_image), ".*(powershell|pwsh)\.exe$") and matches(toLowerCase(command_line), ".*(set-securebootuefi|set-uefivariable|bcdedit.*/set|bcdedit.*/delete).*"), 1, 0)
| eval risk_score = tool_hit + write_hit + (driver_hit * 2) + uefi_hit
| where risk_score > 0
| eval signal = if(driver_hit == 1, "SuspiciousFirmwareDriver",
if(write_hit == 1 and tool_hit == 1, "FirmwareToolWithWriteOp",
if(tool_hit == 1, "KnownFirmwareTool",
if(uefi_hit == 1, "UEFIOrBCDTamper",
if(write_hit == 1, "FirmwareWritePattern", "UnknownFirmwareSignal")))))
| fields _messagetime, hostname, username, process_image, command_line, parent_image, image_loaded, event_id, signal, risk_score
| sort by risk_score desc, _messagetime descSumo Logic CSE query detecting T1495 firmware corruption across Windows Sysmon event logs. Parses Sysmon EventIDs 1 (Process Create), 6 (Driver Load), and 7 (Image Load) to identify known firmware tool execution, write/erase command flags, suspicious kernel driver loads, and UEFI/BCD modification via PowerShell. Risk scoring prioritizes driver loads (weight 2) as highest confidence.
Data Sources
Required Tables
False Positives & Tuning
- Vendor-provided BIOS update packages from Dell Command Update, HP System Software Manager, or Lenovo System Update that silently invoke fpt.exe or h2offt.exe with write flags during automated firmware updates
- Hardware security assessment tools such as Chipsec used legitimately by the platform security or firmware engineering team to audit UEFI configuration on test systems
- Enterprise IT automation scripts using bcdedit to configure BitLocker protectors, enable/disable test signing, or modify boot sequence during provisioning
Other platforms for T1495
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 1CHIPSEC UEFI Variable Enumeration — Read-Only Firmware Reconnaissance
Expected signal: Sysmon Event ID 1: Process Create with Image=python.exe, CommandLine containing 'chipsec_util.py uefi var-list'. Sysmon Event ID 6: Driver load for chipsec.sys (or chipsec_hlpr.sys) from a temp or install directory. Security Event ID 7045: New service installed for the CHIPSEC kernel driver. Windows may prompt for UAC on driver installation.
- Test 2RW-Everything Hardware Access Tool Execution with Ring-0 Driver Load
Expected signal: Sysmon Event ID 1: Process Create with Image=Rw.exe and CommandLine containing '/Command="PCI 0 0 0 0 10"'. Sysmon Event ID 6: Driver load for rw.sys from tool directory or System32\drivers\. Security Event ID 7045: New service named 'RW' registered pointing to rw.sys. Service exits after tool completes but driver load telemetry persists.
- Test 3PowerShell BCD Store Modification — Bad Rabbit Bootloader Tamper Simulation
Expected signal: Sysmon Event ID 1: Process Create for powershell.exe with CommandLine containing 'bcdedit /set' and ExecutionPolicy Bypass. Two additional Sysmon EventCode=1 events for bcdedit.exe child processes. Security Event ID 4688 (if command-line auditing enabled) for both bcdedit invocations. PowerShell ScriptBlock Log Event ID 4104 capturing the full command.
- Test 4Linux flashrom SPI Flash Probe — Non-Destructive Hardware Reconnaissance
Expected signal: Linux auditd EXECVE record with a=flashrom, argv containing '-p', 'internal', '--no-action', '-V'. Syslog entry capturing sudo invocation and flashrom execution. On systems with Sysmon for Linux (EventID 1): Process Create event for flashrom. /var/log/auth.log entry recording sudo authentication for the flashrom command.
- Test 5Intel Flash Programming Tool (FPT) Flash Descriptor Read
Expected signal: Sysmon Event ID 1: Process Create with Image=fptw64.exe, CommandLine containing '-DESC -d'. Sysmon Event ID 11: File Create event for df00tech_flashdesc.bin in %TEMP%. Security Event ID 7045 may appear if FPT installs a kernel service for hardware access. The .bin file size will reflect the flash descriptor region size (typically 4KB).
References (8)
- https://attack.mitre.org/techniques/T1495/
- https://securelist.com/bad-rabbit-ransomware/82851/
- https://eclypsium.com/research/trickbot-now-offers-trickboot-persist-brick-profit/
- https://www.cisa.gov/uscert/ncas/alerts/aa22-057a
- https://cyber.dhs.gov/assets/report/ar-16-20173.pdf
- https://chipsec.github.io/
- https://www.flashrom.org/
- https://web.archive.org/web/20190508170055/https://www.symantec.com/security-center/writeup/2000-122010-2655-99
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