Files
splunk-security_content/detections/endpoint/office_application_drop_executable.yml
Michael Haag 6eb57e394e Haag is Back 🎆
2023-03-10 06:21:30 -07:00

78 lines
3.3 KiB
YAML

name: Office Application Drop Executable
id: 73ce70c4-146d-11ec-9184-acde48001122
version: 4
date: '2023-02-15'
author: Teoderick Contreras, Michael Haag, Splunk, TheLawsOfChaos, Github
type: TTP
datamodel:
- Endpoint
description: This search is to detect a suspicious MS office application that drops
or creates executables or scripts in a Windows Operating System. This behavior is commonly seen in spear
phishing office attachment where it drop malicious files or script to compromised
the host. It might be some normal macro may drop script or tools as part of automation
but still this behavior is reallly suspicious and not commonly seen in normal office
application
search: '| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes
where Processes.process_name IN ("winword.exe","excel.exe","powerpnt.exe","mspub.exe","visio.exe","wordpad.exe","wordview.exe","onenote.exe","onenotem.exe","onenoteviewer.exe","onenoteim.exe","msaccess.exe")
by _time span=1h Processes.process_id Processes.process_name Processes.process Processes.dest
Processes.process_guid | `drop_dm_object_name(Processes)` |join process_guid, _time [| tstats `security_content_summariesonly` count
min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem
where Filesystem.file_name IN ("*.exe","*.dll","*.pif","*.scr","*.js","*.vbs","*.vbe","*.ps1")
by _time span=1h Filesystem.dest Filesystem.file_create_time Filesystem.file_name
Filesystem.process_guid Filesystem.file_path | `drop_dm_object_name(Filesystem)`
| fields _time dest file_create_time file_name
file_path process_name process_path process process_guid] | dedup file_create_time
| table dest, process_name, process, file_create_time, file_name, file_path, process_guid
| `office_application_drop_executable_filter`'
how_to_implement: To successfully implement this search, you need to be ingesting
logs with the process name, parent process, and command-line executions from your
endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the
Sysmon TA. Tune and filter known instances where renamed rundll32.exe may be used.
known_false_positives: office macro for automation may do this behavior
references:
- https://www.mandiant.com/resources/fin7-pursuing-an-enigmatic-and-evasive-global-criminal-operation
- https://attack.mitre.org/groups/G0046/
- https://www.joesandbox.com/analysis/702680/0/html
- https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/trojanized-onenote-document-leads-to-formbook-malware/
tags:
analytic_story:
- FIN7
- AgentTesla
- CVE-2023-21716 Word RTF Heap Corruption
confidence: 80
context:
- Source:Endpoint
- Stage:Recon
dataset:
- https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/fin7/fin7_macro_js_1/sysmon.log
impact: 80
kill_chain_phases:
- Exploitation
message: process $process_name$ drops a file $file_name$ in host $dest$
mitre_attack_id:
- T1566
- T1566.001
observable:
- name: dest
type: Hostname
role:
- Victim
- name: process_name
type: Process
role:
- Attacker
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
required_fields:
- _time
- process_name
- file_name
- process_guid
- dest
- user_id
risk_score: 64
security_domain: endpoint
asset_type: Endpoint