Network Boundary Bridging T1599

Tactic: Defense Impairment

Adversaries may bridge network boundaries by compromising perimeter network devices or internal devices responsible for network segmentation. Breaching these devices may enable an adversary to bypass restrictions on traffic routing that otherwise separate trusted and untrusted networks.

Events covered

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

ProviderEventTitle
SysmonEvent ID 6Driver loaded

Authoring guide

Patterns shared across the 6 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 (9 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
Hashes1contains 1imphash=0604bb7cb4bb851e2168d5c7d9399087, imphash=0ea54f8c9af4a2fe8367fa457f48ed38, imphash=2a5f85fe4609461c6339637594fa9b0a
ImageLoaded1contains 1\eswfp.sys, \lingtiwfp.sys, \norddivert.sys
SyslogMessage1contains 1packet too big, vcf drop
aws::errorCode1eq 1VpceAccessDenied
aws::eventSource1in 1cloudtrail.amazonaws.com, ec2.amazonaws.com, kms.amazonaws.com
aws::userIdentity.type1eq 1AWSAccount
recipientAccountId1cross_field_compare 1, is_not_null 1userIdentity.accountId
userIdentity1contains 1principalid
userIdentity.accountId1is_not_null 1

Top indicator values (34 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
Hashescontains
imphash=0604bb7cb4bb851e2168d5c7d9399087
1
Hashescontains
imphash=0ea54f8c9af4a2fe8367fa457f48ed38
1
Hashescontains
imphash=2a5f85fe4609461c6339637594fa9b0a
1
Hashescontains
imphash=2e5f0e649d97f32b03c09e4686d0574f
1
Hashescontains
imphash=45ee545ae77e8d43fc70ede9efcd4c96
1
Hashescontains
imphash=52f8aa269f69f0edad9e8fcdaedce276
1
Hashescontains
imphash=58623490691babe8330adc81cd04a663
1
Hashescontains
imphash=6b2c6f95233c2914d1d488ee27531acc
1
Hashescontains
imphash=8ee39b48656e4d6b8459d7ba7da7438b
1
Hashescontains
imphash=9d519ae0a0864d6d6ae3f8b6c9c70af6
1
Hashescontains
imphash=9f2fdd3f9ab922bbb0560a7df46f4342
1
Hashescontains
imphash=a1b2e245acd47e4a348e1a552a02859a
1
Hashescontains
imphash=a66b476c2d06c370f0a53b5537f2f11e
1
Hashescontains
imphash=a74929edfc3289895e3f2885278947ae
1
Hashescontains
imphash=bdcd836a46bc2415773f6b5ea77a46e4
1
Hashescontains
imphash=c0e5d314da39dbf65a2dbff409cc2c76
1
Hashescontains
imphash=c28cd6ccd83179e79dac132a553693d9
1
Hashescontains
imphash=d8a719865c448b1bd2ec241e46ac1c88
1
ImageLoadedcontains
\eswfp.sys
1
ImageLoadedcontains
\lingtiwfp.sys
1
ImageLoadedcontains
\norddivert.sys
1
ImageLoadedcontains
\windivert.sys
1
ImageLoadedcontains
\windivert64.sys
1
SyslogMessagecontains
packet too big
1
SyslogMessagecontains
vcf drop
12
aws::errorCodeeq
VpceAccessDenied
1
aws::eventSourcein
cloudtrail.amazonaws.com
1
aws::eventSourcein
ec2.amazonaws.com
1
aws::eventSourcein
kms.amazonaws.com
1
aws::eventSourcein
s3.amazonaws.com
1

Exclusions (3 distinct)

Field/operator/value combinations excluded by rules under this technique (top-level not() clauses), sorted by how many rules exclude each. These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths. Click a value to expand the rules under this technique that exclude it.

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)

Sigma 1 rule

Kusto 1 rule

Panther 4 rules