Detection rules › Sigma

Potentially Suspicious Self Extraction Directive File Created

Severity
medium
Author
Joseliyo Sanchez, @Joseliyo_Jstnk
Source
upstream

Detects the creation of a binary file with the ".sed" extension. The ".sed" extension stand for Self Extraction Directive files. These files are used by the "iexpress.exe" utility in order to create self extracting packages. Attackers were seen abusing this utility and creating PE files with embedded ".sed" entries. Usually ".sed" files are simple ini files and not PE binaries.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1218 System Binary Proxy Execution

Event coverage

ProviderEvent IDTitle
Sysmon29FileExecutableDetected

Stages and Predicates

Stage 1: selection

TargetFilename|endswith: .sed

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
TargetFilenameends_with
  • .sed corpus 2 (sigma 2)

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.