ATT&CK coverage › Technique
External Remote Services T1133
Adversaries may leverage external-facing remote services to initially access and/or persist within a network. Remote services such as VPNs, Citrix, and other access mechanisms allow users to connect to internal enterprise network resources from external locations. There are often remote service gateways that manage connections and credential authentication for these services. Services such as Windows Remote Management and VNC can also be used externally.
Events covered
11 catalog events are tagged with this technique by at least one rule.
Authoring guide
Patterns shared across the 17 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized 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 (12 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 (211 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.
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 11 rules
- External Remote RDP Logon from Public IP
- External Remote SMB Logon from Public IP
- Failed Logon From Public IP
- Remote Access Tool - ScreenConnect Installation Execution
- Remote Access Tool - Team Viewer Session Started On Windows Host
- Running Chrome VPN Extensions via the Registry 2 VPN Extension
- Suspicious File Created by ArcSOC.exe
- Unusual Child Process of dns.exe
- Unusual File Deletion by Dns.exe
- Unusual File Modification by dns.exe
- User Added to Remote Desktop Users Group