Filter Driver Unloaded Via Fltmc.EXE

Severity: medium
Author: Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detect filter driver unloading activity via fltmc.exe

MITRE ATT&CK coverage

Tactic	Techniques
Defense Evasion	`T1070` Indicator Removal, `T1562` Impair Defenses, `T1562.002` Impair Defenses: Disable Windows Event Logging

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_img`

or:
Image|endswith: '\fltMC.exe'
OriginalFileName: fltMC.exe

Stage 2: `all of selection_cli`

CommandLine|contains: unload

Stage 3: `not 1 of filter_optional_*`

or:
or:
CommandLine|endswith: 'unload rtp_filesystem_filter'
CommandLine|endswith: 'unload rtp_filter'
or:
ParentImage|contains: ':\Windows\Temp\'
ParentImage|contains: '\AppData\Local\Temp\'
ParentImage|endswith: '\endpoint-protection-installer-x64.tmp'
CommandLine|endswith: 'unload DFMFilter'
ParentImage: 'C:\Program Files (x86)\ManageEngine\uems_agent\bin\dcfaservice64.exe'

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.

Field	Kind	Values
`CommandLine`	ends_with	`unload DFMFilter` `unload rtp_filesystem_filter` `unload rtp_filter`
`CommandLine`	match	`unload` corpus 2 (sigma 2)
`Image`	ends_with	`\fltMC.exe` corpus 2 (sigma 2)
`OriginalFileName`	eq	`fltMC.exe` corpus 2 (sigma 2)
`ParentImage`	ends_with	`\endpoint-protection-installer-x64.tmp`
`ParentImage`	eq	`C:\Program Files (x86)\ManageEngine\uems_agent\bin\dcfaservice64.exe`
`ParentImage`	match	`:\Windows\Temp\` corpus 4 (sigma 4) `\AppData\Local\Temp\` corpus 4 (sigma 4)