Fallback Channels T1008
Tactic: Command & Control
Adversaries may use fallback or alternate communication channels if the primary channel is compromised or inaccessible in order to maintain reliable command and control and to avoid data transfer thresholds.
Events covered
3 catalog events are tagged with this technique by at least one rule.
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 11 | FileCreate |
| Sysmon | Event ID 13 | RegistryEvent (Value Set) |
| Sysmon | Event ID 22 | DNSEvent (DNS query) |
Authoring guide
Patterns shared across the 16 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 (27 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.
Top indicator values (69 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.
Exclusions (11 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.
Sigma 4 rules
- New Outlook Macro Created
- Outlook Macro Execution Without Warning Setting Enabled
- Potential Persistence Via Outlook LoadMacroProviderOnBoot Setting
- Suspicious Outlook Macro Created
Splunk 1 rule
Kusto 11 rules
- Detect DNS queries reporting multiple errors from different clients - Anomaly Based (ASIM DNS Solution)
- Detect DNS queries reporting multiple errors from different clients - Static threshold based (ASIM DNS Solution)
- Detect excessive NXDOMAIN DNS queries - Anomaly based (ASIM DNS Solution)
- Detect excessive NXDOMAIN DNS queries - Static threshold based (ASIM DNS Solution)
- Excessive NXDOMAIN DNS Queries
- Excessive NXDOMAIN DNS Queries (ASIM DNS Schema)
- Potential DGA detected
- Potential DGA detected (ASIM DNS Schema)
- Potential DGA(Domain Generation Algorithm) detected via Repetitive Failures - Anomaly based (ASIM DNS Solution)
- Potential DGA(Domain Generation Algorithm) detected via Repetitive Failures - Static threshold based (ASIM DNS Solution)
- Squid proxy events for ToR proxies