Unused/Unsupported Cloud Regions T1535

Tactic: Stealth

Adversaries may create cloud instances in unused geographic service regions in order to evade detection. Access is usually obtained through compromising accounts used to manage cloud infrastructure.

Authoring guide

Patterns shared across the 10 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 (16 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
signature3eq 3ConsoleLogin
aws::eventName2eq 2ConsoleLogin, EnableRegion
All_Changes.action1eq 1created
EventID1eq 1DisableRegion, EnableRegion
aws::eventSource1eq 1ecr.amazonaws.com
awsRegion1in 1ap-east-1, eu-central-1, eu-west-3
distinct_ip_count1gt 11
enough_data1eq 11
firstTimeSeenRegion1gt 1, is_null 1
protoPayload.methodName1ends_with 1create, insert
readOnly1eq 1False
security_result.action1eq 1ALLOW
sourcetype1eq 1aws:cloudtrail
userCity1eq 1New City
userCountry1eq 1New Country

Top indicator values (20 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
signatureeq
ConsoleLogin
34
All_Changes.actioneq
created
111
EventIDeq
DisableRegion
1
EventIDeq
EnableRegion
1
aws::eventNameeq
ConsoleLogin
127
aws::eventNameeq
EnableRegion
12
aws::eventSourceeq
ecr.amazonaws.com
17
awsRegionin
ap-east-1
1
awsRegionin
eu-central-1
1
awsRegionin
eu-west-3
1
distinct_ip_countgt
1
14
enough_dataeq
1
110
protoPayload.methodNameends_with
create
1
protoPayload.methodNameends_with
insert
1
readOnlyeq
False
1
security_result.actioneq
ALLOW
1102
sourcetypeeq
aws:cloudtrail
159
userCityeq
New City
1
userCountryeq
New Country
1
userRegioneq
New Region
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)

Splunk 5 rules

YARA-L 1 rule

Panther 4 rules