Exfiltration Over Alternative Protocol: Exfiltration Over Asymmetric Encrypted Non-C2 Protocol T1048.002

Tactic: Exfiltration

Adversaries may steal data by exfiltrating it over an asymmetrically encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.

Authoring guide

Patterns shared across the 4 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 (7 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
EventID4eq 4FileDownloaded, AnonymousLinkUsed, FileAccessed, Microsoft Graph Activity
SubjectUserName3eq 3, regex_match 2anonymous, ^urn:spo:anon#
metadata.event_type1eq 1
metadata.product_name1eq 1
metadata.vendor_name1eq 1
network.http.method1eq 1GET
network.http.response_code1eq 1302

Top indicator values (8 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
SubjectUserNameeq
anonymous
33
EventIDeq
FileDownloaded
22
EventIDeq
AnonymousLinkUsed
1
EventIDeq
FileAccessed
1
EventIDeq
Microsoft Graph Activity
120
SubjectUserNameregex_match
^urn:spo:anon#
22
network.http.methodeq
GET
114
network.http.response_codeeq
302
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)

YARA-L 4 rules