Proxy: Multi-hop Proxy T1090.003
Tactic: Command & Control
Adversaries may chain together multiple proxies to disguise the source of malicious traffic. Typically, a defender will be able to identify the last proxy traffic traversed before it enters their network; the defender may or may not be able to identify any previous proxies before the last-hop proxy. This technique makes identifying the original source of the malicious traffic even more difficult by requiring the defender to trace malicious traffic through several proxies to identify its source.
Events covered
6 catalog events are tagged with this technique by at least one rule.
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Sysmon | Event ID 3 | Network connection |
| Sysmon | Event ID 22 | DNSEvent (DNS query) |
| Security-Auditing | Event ID 4688 | A new process has been created. |
| Security-Auditing | Event ID 5156 | The Windows Filtering Platform has permitted a connection. |
| DNS-Client | Event ID 3008 | DNS query is completed for the name QueryName, type QueryType, query options QueryOptions with status QueryStatus Results QueryResults. |
Authoring guide
Patterns shared across the 13 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 (26 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 (115 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.
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 3 rules
- DNS Query Tor .Onion Address - Sysmon
- Query Tor Onion Address - DNS Client
- Tor Client/Browser Execution