Detection rules › Splunk

File Executed from INetCache (Windows Event Log)

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

Adversaries may transfer tools or other files from an external system into a compromised environment. Tools or files may be copied from an external adversary-controlled system to the victim network through the command and control channel or through alternate protocols such as ftp. Once present, adversaries may also transfer/spread tools between victim devices within a compromised environment (i.e. Lateral Tool Transfer). This use case detects when a file was executed from the C:\Users<user>\AppData\Local\Microsoft\Windows\INetCache\IE folder.

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1105 Ingress Tool Transfer

References

Event coverage

Rule body yaml

id: '35400.62241'
title: File Executed from INetCache
description: Adversaries may transfer tools or other files from an external system
  into a compromised environment. Tools or files may be copied from an external adversary-controlled
  system to the victim network through the command and control channel or through
  alternate protocols such as ftp. Once present, adversaries may also transfer/spread
  tools between victim devices within a compromised environment (i.e. Lateral Tool
  Transfer). This use case detects when a file was executed from the C:\Users\<user>\AppData\Local\Microsoft\Windows\INetCache\IE
  folder.
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
  "<EventID>4688<" OR Type=Process) "\\AppData\\Local\\Microsoft\\Windows\\INetCache\\IE"
  | regex process_path="(?i)\x5cAppData\x5cLocal\x5cMicrosoft\x5cWindows\x5cINetCache\x5cIE"
  | table _time, host, user, process, process_*, parent_* | bin span=1s | stats values(*)
  as * by _time, host '
techniques:
- command-and-control:ingress tool transfer
technique_id: 
- T1105
data_category:
- Windows event logs
references:
- https://lolbas-project.github.io/lolbas/Binaries/Ngen/
- https://learn.microsoft.com/en-us/dotnet/framework/tools/ngen-exe-native-image-generator
- https://attack.mitre.org/techniques/T1105/
- https://www.elastic.co/guide/en/security/8.14/suspicious-execution-from-inet-cache.html

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR "<EventID>4688<" OR Type=Process) "\\AppData\\Local\\Microsoft\\Windows\\INetCache\\IE"

Stage 2: regex

| regex process_path="(?i)\x5cAppData\x5cLocal\x5cMicrosoft\x5cWindows\x5cINetCache\x5cIE"

Stage 3: table

| table _time, host, user, process, process_*, 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
  • 4688 corpus 313 (splunk 283, kusto 30)
process_pathregex_match
  • "(?i)\x5cAppData\x5cLocal\x5cMicrosoft\x5cWindows\x5cINetCache\x5cIE" corpus 2 (splunk 2)

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>4688<"
1"\\AppData\\Local\\Microsoft\\Windows\\INetCache\\IE"