Detection rules › Splunk
Windows File Transfer Protocol In Non-Common Process Path
The following analytic detects FTP connections initiated by processes located in non-standard installation paths on Windows systems. It leverages Sysmon EventCode 3 to identify network connections where the process image path does not match common directories like "Program Files" or "Windows\System32". This activity is significant as FTP is often used by adversaries and malware, such as AgentTesla, for Command and Control (C2) communications to exfiltrate stolen data. If confirmed malicious, this could lead to unauthorized data transfer, exposing sensitive information and compromising the integrity of the affected host.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control | T1071.003 Application Layer Protocol: Mail Protocols |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 3 | Network connection |
Stages and Predicates
Stage 1: search
search (DestinationPort=21 OR DestinationPortName="ftp") NOT Image IN ("C:\\Program Files \(x86\)\\*", "C:\\Program Files\\*", "C:\\Windows\\SysWOW64\\*", "C:\\Windows\\System32\\*") EventCode=3
Stage 2: stats
stats BY action, app, dest, dest_ip, dest_port, direction, dvc, protocol, protocol_version, src, src_ip, src_port, transport, user, vendor_product, process_name, process_exec, process_guid, process_id
Stage 3: search
search
Stage 4: search
search
Stage 5: search
search `macro`
Exclusions
Top-level NOT(...) conjuncts — predicates this rule actively suppresses.
| Stage | Field | Kind | Excluded values |
|---|---|---|---|
| 1 | Image | in | "C:\\Program Files \(x86\)\\*", "C:\\Program Files\\*", "C:\\Windows\\SysWOW64\\*", "C:\\Windows\\System32\\*" |
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
DestinationPort | eq |
|
DestinationPortName | eq |
|
EventCode | eq |
|