Potential Rcdll.DLL Sideloading

Severity: high
Author: X__Junior (Nextron Systems)
Source: upstream

Detects potential DLL sideloading of rcdll.dll

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`

ImageLoaded|endswith: '\rcdll.dll'

Stage 2: `not filter`

or:
ImageLoaded|startswith: 'C:\Program Files (x86)\Microsoft Visual Studio\'
ImageLoaded|startswith: 'C:\Program Files (x86)\Windows Kits\'

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
`ImageLoaded`	ends_with	`\rcdll.dll`
`ImageLoaded`	starts_with	`C:\Program Files (x86)\Microsoft Visual Studio\` `C:\Program Files (x86)\Windows Kits\` corpus 3 (sigma 3)