Suspicious Unsigned Thor Scanner Execution

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

Detects loading and execution of an unsigned thor scanner binary.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1574.001` Hijack Execution Flow: DLL
Privilege Escalation	`T1574.001` Hijack Execution Flow: DLL
Defense Evasion	`T1574.001` Hijack Execution Flow: DLL

Event coverage

Provider	Event ID	Title
Sysmon	7	Image loaded

Stages and Predicates

Stage 1: `selection`

or:
Image|endswith: '\thor.exe'
Image|endswith: '\thor64.exe'
or:
ImageLoaded|endswith: '\thor.exe'
ImageLoaded|endswith: '\thor64.exe'

Stage 2: `not filter_main`

Signature: 'Nextron Systems GmbH'
SignatureStatus: valid
Signed: true

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	`\thor.exe` corpus 7 (sigma 7) `\thor64.exe` corpus 6 (sigma 6)
`ImageLoaded`	ends_with	`\thor.exe` `\thor64.exe`
`Signature`	eq	`Nextron Systems GmbH`
`SignatureStatus`	eq	`valid`
`Signed`	eq	`true` corpus 8 (sigma 8)