Detection rules › Sigma

Amsi.DLL Loaded Via LOLBIN Process

Severity
medium
Author
Nasreddine Bencherchali (Nextron Systems)
Source
upstream

Detects loading of "Amsi.dll" by a living of the land process. This could be an indication of a "PowerShell without PowerShell" attack

Event coverage

ProviderEvent IDTitle
Sysmon7Image loaded

Stages and Predicates

Stage 1: selection

or:
Image|endswith: '\ExtExport.exe'
Image|endswith: '\odbcconf.exe'
Image|endswith: '\rundll32.exe'
ImageLoaded|endswith: '\amsi.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.

FieldKindValues
Imageends_with
  • \ExtExport.exe
  • \odbcconf.exe corpus 11 (sigma 11)
  • \rundll32.exe corpus 76 (sigma 76)
ImageLoadedends_with
  • \amsi.dll corpus 2 (sigma 2)