Potential DLL Sideloading Of DBGCORE.DLL

Severity: medium
Author: Nasreddine Bencherchali (Nextron Systems), Wietze Beukema (project and research)
Source: upstream

Detects DLL sideloading of "dbgcore.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: '\dbgcore.dll'

Stage 2: `not 1 of filter_main_generic`

or:
ImageLoaded|startswith: 'C:\Program Files (x86)\'
ImageLoaded|startswith: 'C:\Program Files\'
ImageLoaded|startswith: 'C:\Windows\SoftwareDistribution\'
ImageLoaded|startswith: 'C:\Windows\SysWOW64\'
ImageLoaded|startswith: 'C:\Windows\System32\'
ImageLoaded|startswith: 'C:\Windows\SystemTemp\'
ImageLoaded|startswith: 'C:\Windows\WinSxS\'

Stage 3: `not 1 of filter_optional_*`

or:
ImageLoaded|endswith: '\assistant\dbgcore.dll'
ImageLoaded|contains: 'opera\Opera Installer Temp\opera_package'
ImageLoaded|endswith: '\Steam\bin\cef\cef.win7x64\dbgcore.dll'

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	`\Steam\bin\cef\cef.win7x64\dbgcore.dll` `\assistant\dbgcore.dll` `\dbgcore.dll` corpus 4 (sigma 4)
`ImageLoaded`	match	`opera\Opera Installer Temp\opera_package` corpus 2 (sigma 2)
`ImageLoaded`	starts_with	`C:\Program Files (x86)\` corpus 6 (sigma 6) `C:\Program Files\` corpus 6 (sigma 6) `C:\Windows\SoftwareDistribution\` corpus 2 (sigma 2) `C:\Windows\SysWOW64\` corpus 8 (sigma 8) `C:\Windows\System32\` corpus 8 (sigma 8) `C:\Windows\SystemTemp\` corpus 2 (sigma 2) `C:\Windows\WinSxS\` corpus 9 (sigma 9)