ATT&CK coverage › Technique

Proxy T1090

Adversaries may use a connection proxy to direct network traffic between systems or act as an intermediary for network communications to a command and control server to avoid direct connections to their infrastructure. Many tools exist that enable traffic redirection through proxies or port redirection, including HTRAN, ZXProxy, and ZXPortMap. Adversaries use these types of proxies to manage command and control communications, reduce the number of simultaneous outbound network connections, provide resiliency in the face of connection loss, or to ride over existing trusted communications paths between victims to avoid suspicion. Adversaries may chain together multiple proxies to further disguise the source of malicious traffic.

Events covered

9 catalog events are tagged with this technique by at least one rule.

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon3Network connection
Sysmon12RegistryEvent (Object create and delete)
Sysmon13RegistryEvent (Value Set)
Sysmon14RegistryEvent (Key and Value Rename)
Sysmon22DNSEvent (DNS query)
Security-Auditing4688A new process has been created.
PowerShell4104Creating Scriptblock text (MessageNumber of MessageTotal).
TerminalServices-LocalSessionManager21Remote Desktop Services: Session logon succeeded.

Authoring guide

Patterns shared across the 16 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 (11 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
CommandLine9match 9 tunnel , cleanup , -connector-id , run , -credentials-contents
Image6ends_with 6\netsh.exe, \htran.exe, \lcx.exe, \frps.exe, \frpc.exe
Hashes3match 3MD5=7D9C233B8C9E3F0EA290D2B84593C842, SHA256=57B0936B8D336D8E981C169466A15A5FD21A7D5A2C7DAF62D5..., SHA1=06DDC9280E1F1810677935A2477012960905942F, SHA256=5A456283392FFCEEEACA3D3426C306EB470304637520D72FED..., MD5=AE8ACF66BFE3A44148964048B826D005
DestinationHostname2ends_with 1, match 1.localto.net, .localtonet.com, tunnel.in.ngrok.com, tunnel.sa.ngrok.com, tunnel.au.ngrok.com
OriginalFileName2eq 2netsh.exe
DnsQuery1is_not_null 1, match 1NgrokDomains
Initiated1eq 1true
TargetObject1match 1\Services\PortProxy\v4tov4\tcp\
Address1match 116777216
ScriptBlockText1match 1[System.Net.HttpWebRequest], AcceptTcpClient, System.Net.Sockets.TcpListener
dns.question.name1in 1"*.ngrok.io", "*.ngrok.com", "korgn.*.lennut.com"

Top indicator values (81 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.

FieldKindValueRules (here)Corpus reach
CommandLinematch-config 23
CommandLinematch tunnel 23
Imageends_with\netsh.exe216
OriginalFileNameeqnetsh.exe214
DnsQuerymatchNgrokDomains1
CommandLinematchcleanup 12
CommandLinematch-connector-id 12
CommandLinematch-credentials-contents 12
CommandLinematch-credentials-file 12
CommandLinematch-token 12
CommandLinematch run 12
Initiatedeqtrue140
DestinationHostnameends_with.localtonet.com1
DestinationHostnameends_with.localto.net1
DestinationHostnamematchtunnel.au.ngrok.com1
DestinationHostnamematchtunnel.us.ngrok.com1
DestinationHostnamematchtunnel.eu.ngrok.com1
DestinationHostnamematchtunnel.jp.ngrok.com1
DestinationHostnamematchtunnel.sa.ngrok.com1
DestinationHostnamematchtunnel.ap.ngrok.com1

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 14 rules

Splunk 1 rule

Kusto Query Language 1 rule