ATT&CK coverage › Technique

Office Application Startup: Outlook Forms T1137.003

Adversaries may abuse Microsoft Outlook forms to obtain persistence on a compromised system. Outlook forms are used as templates for presentation and functionality in Outlook messages. Custom Outlook forms can be created that will execute code when a specifically crafted email is sent by an adversary utilizing the same custom Outlook form.

Events covered

1 catalog event are tagged with this technique by at least one rule.

ProviderEvent IDTitle
Sysmon11FileCreate

Authoring guide

Patterns shared across the 1 rule above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.

Fields filtered most (2 distinct)

The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.

FieldRulesHowSample values
Image1ends_with 1\outlook.exe
TargetFilename1match 1\Local Settings\Application Data\Microsoft\Forms, \AppData\Local\Microsoft\FORMS\IPM

Top indicator values (3 distinct)

Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique.

FieldKindValueRules (here)Corpus reach
Imageends_with\outlook.exe116
TargetFilenamematch\AppData\Local\Microsoft\FORMS\IPM1
TargetFilenamematch\Local Settings\Application Data\Microsoft\Forms1

Rules under this technique

Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.

Sigma 1 rule