Spearphishing Attachment T0865

ICS Tactic: Initial Access

Authoring guide

Patterns shared across the 5 rules above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names 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 (10 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
Action1ne 1allow
Active1eq 1true
DataverseActivity_TimeGenerated1lt 1ExpirationDateTime
Fields1contains 1, is_not_null 1http
Message1in 1Create, Update
Result1ne 1safe
Scan Result1eq 1malicious
Type1eq 1email_ttp_ap
Url1is_not_null 1
mimecastEventId_s1eq 1mail_ttp_attachment

Top indicator values (10 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. Click a value to expand the rules under this technique that use it.

FieldKindValueRules (here)Corpus reach
Actionne
allow
1
Activeeq
true
168
DataverseActivity_TimeGeneratedlt
ExpirationDateTime
12
Fieldscontains
http
1
Messagein
Create
12
Messagein
Update
13
Resultne
safe
1
Scan Resulteq
malicious
1
Typeeq
email_ttp_ap
1
mimecastEventId_seq
mail_ttp_attachment
1

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.

Platform (all)
Domain (all)

Kusto 5 rules