HackTool - SysmonEnte Execution

Severity: high
Author: Florian Roth (Nextron Systems)
Source: upstream

Detects the use of SysmonEnte, a tool to attack the integrity of Sysmon

MITRE ATT&CK coverage

Tactic	Techniques
Defense Evasion	`T1562.002` Impair Defenses: Disable Windows Event Logging

Event coverage

Provider	Event ID	Title
Sysmon	10	ProcessAccess

Stages and Predicates

Stage 1: `selection_sysmon`

or:
TargetImage|contains: ':\Windows\Sysmon.exe'
TargetImage|contains: ':\Windows\Sysmon64.exe'
GrantedAccess: 0x1400

Stage 2: `not 1 of filter_main_*`

or:
SourceImage|endswith: '\MsMpEng.exe'
SourceImage|contains: ':\ProgramData\Microsoft\Windows Defender\Platform\'
SourceImage|contains: ':\Program Files (x86)\'
SourceImage|contains: ':\Program Files\'
SourceImage|contains: ':\Windows\SysWOW64\'
SourceImage|contains: ':\Windows\System32\'

Stage 3: `selection_calltrace`

CallTrace: Ente

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
`CallTrace`	eq	`Ente`
`GrantedAccess`	eq	`0x1400`
`SourceImage`	ends_with	`\MsMpEng.exe` corpus 13 (sigma 13)
`SourceImage`	match	`:\Program Files (x86)\` corpus 4 (sigma 4) `:\Program Files\` corpus 6 (sigma 6) `:\ProgramData\Microsoft\Windows Defender\Platform\` corpus 2 (sigma 2) `:\Windows\SysWOW64\` corpus 7 (sigma 7) `:\Windows\System32\` corpus 6 (sigma 6)
`TargetImage`	match	`:\Windows\Sysmon.exe` `:\Windows\Sysmon64.exe`