Detection rules › Splunk

Windows FTP Exfiltration (Sysmon)

Group by
_time, host
Source
github.com/anvilogic-forge/armory

FTP is a utility commonly available with operating systems to transfer information over the File Transfer Protocol (FTP). Adversaries can use it to transfer other tools onto a system or to exfiltrate data

MITRE ATT&CK coverage

References

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

id: '5704.18099'
title: Windows FTP Exfiltration
description: 'FTP is a utility commonly available with operating systems to transfer
  information over the File Transfer Protocol (FTP). Adversaries can use it to transfer
  other tools onto a system or to exfiltrate data. - Threat Actor Association: APT35,
  Karakurt - Software Association: Agent Tesla, BianLian, Diavol, PureCrypter'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "EventID>1<")
  TERM(ftp) | regex process="(?i)ftp\s+(.{1,})?\-s\:.{1,}\.\w{2,5}" | table _time,
  host, user process, process_*, signature_id, parent_* | bin span=1s | stats values(*)
  as * by _time, host '
techniques:
- command-and-control:application layer protocol:file transfer protocols
- exfiltration:exfiltration over alternative protocol
technique_id:
- T1071.002
- T1048
data_category:
- Windows Sysmon
references:
- https://book.hacktricks.xyz/exfiltration

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "EventID>1<") TERM(ftp)

Stage 2: regex

| regex process="(?i)ftp\s+(.{1,})?\-s\:.{1,}\.\w{2,5}"

Stage 3: table

| table _time, host, user process, process_*, signature_id, parent_*

Stage 4: bucket

| bin span=1s

Stage 5: stats

| stats values(*) as * by _time, host

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.

FieldKindValues
EventCodeeq
  • 1 corpus 237 (splunk 224, kusto 13)
processregex_match
  • "(?i)ftp\s+(.{1,})?\-s\:.{1,}.\w{2,5}" corpus 3 (splunk 3)

Search terms

Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.

StageTerm
1TERM
1"EventID>1<"
1TERM
1ftp