Usage of Renamed Sysinternals Tools - RegistrySet

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

Detects non-sysinternals tools setting the "accepteula" key which normally is set on sysinternals tool execution

MITRE ATT&CK coverage

Tactic	Techniques
Resource Development	`T1588.002` Obtain Capabilities: Tool

Event coverage

Provider	Event ID	Title
Sysmon	13	RegistryEvent (Value Set)

Stages and Predicates

Stage 1: `selection`

or:
TargetObject|contains: '\Active Directory Explorer'
TargetObject|contains: '\Handle'
TargetObject|contains: '\LiveKd'
TargetObject|contains: '\ProcDump'
TargetObject|contains: '\Process Explorer'
TargetObject|contains: '\PsExec'
TargetObject|contains: '\PsLoglist'
TargetObject|contains: '\PsPasswd'
TargetObject|endswith: '\EulaAccepted'

Stage 2: `not 1 of filter_main_image_names`

or:
Image|endswith: '\ADExplorer.exe'
Image|endswith: '\ADExplorer64.exe'
Image|endswith: '\PsExec.exe'
Image|endswith: '\PsExec64.exe'
Image|endswith: '\handle.exe'
Image|endswith: '\handle64.exe'
Image|endswith: '\livekd.exe'
Image|endswith: '\livekd64.exe'
Image|endswith: '\procdump.exe'
Image|endswith: '\procdump64.exe'
Image|endswith: '\procexp.exe'
Image|endswith: '\procexp64.exe'
Image|endswith: '\psloglist.exe'
Image|endswith: '\psloglist64.exe'
Image|endswith: '\pspasswd.exe'
Image|endswith: '\pspasswd64.exe'

Stage 3: `not 1 of filter_optional_null`

Image: null

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
`Image`	ends_with	`\ADExplorer.exe` corpus 6 (sigma 6) `\ADExplorer64.exe` corpus 6 (sigma 6) `\PsExec.exe` corpus 2 (sigma 2) `\PsExec64.exe` corpus 2 (sigma 2) `\handle.exe` corpus 5 (sigma 5) `\handle64.exe` corpus 5 (sigma 5) `\livekd.exe` corpus 7 (sigma 7) `\livekd64.exe` corpus 5 (sigma 5) `\procdump.exe` corpus 6 (sigma 6) `\procdump64.exe` corpus 5 (sigma 5) `\procexp.exe` corpus 6 (sigma 6) `\procexp64.exe` corpus 6 (sigma 6) `\psloglist.exe` corpus 4 (sigma 4) `\psloglist64.exe` corpus 4 (sigma 4) `\pspasswd.exe` corpus 3 (sigma 3) `\pspasswd64.exe` corpus 3 (sigma 3)
`TargetObject`	ends_with	`\EulaAccepted` corpus 4 (sigma 4)
`TargetObject`	match	`\Active Directory Explorer` corpus 3 (sigma 3) `\Handle` corpus 3 (sigma 3) `\LiveKd` corpus 3 (sigma 3) `\ProcDump` corpus 3 (sigma 3) `\Process Explorer` corpus 3 (sigma 3) `\PsExec` corpus 3 (sigma 3) `\PsLoglist` corpus 3 (sigma 3) `\PsPasswd` corpus 3 (sigma 3)

Neighbors

Broader alternatives (more inclusive than this rule)

These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.

PUA - Sysinternal Tool Execution - Registry [sigma] (drops 1 filter this rule applies) (first-stage match only; downstream stages may differ)