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splunk-security_content/dev/endpoint/suspicious_msbuild_path.yml
2023-01-20 13:24:15 +01:00

72 lines
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YAML

name: Suspicious msbuild path
id: f5198224-551c-11eb-ae93-0242ac130002
version: 3
date: '2022-03-08'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic identifies msbuild.exe executing from a non-standard
path. Msbuild.exe is natively found in C:\Windows\Microsoft.NET\Framework\v4.0.30319
and C:\Windows\Microsoft.NET\Framework64\v4.0.30319. Instances of Visual Studio
will run a copy of msbuild.exe. A moved instance of MSBuild is suspicious, however
there are instances of build applications that will move or use a copy of MSBuild.
data_source:
- Sysmon Event ID 1
search:
selection1:
OriginalFileName: MSBuild.exe
selection2:
Image|endswith: msbuild.exe
selection3:
Processes.process_path: '*\\framework*\\v*\\*'
condition: (selection1 or selection2) and selection3
how_to_implement: To successfully implement this search you need to be ingesting information
on process that include the name of the process responsible for the changes from
your endpoints into the `Endpoint` datamodel in the `Processes` node. In addition,
confirm the latest CIM App 4.20 or higher is installed and the latest TA for the
endpoint product.
known_false_positives: Some legitimate applications may use a moved copy of msbuild.exe,
triggering a false positive. Baselining of MSBuild.exe usage is recommended to better
understand it's path usage. Visual Studio runs an instance out of a path that will
need to be filtered on.
references:
- https://lolbas-project.github.io/lolbas/Binaries/Msbuild/
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1127.001/T1127.001.md
tags:
analytic_story:
- Trusted Developer Utilities Proxy Execution MSBuild
- Cobalt Strike
- Masquerading - Rename System Utilities
- Living Off The Land
asset_type: Endpoint
confidence: 70
impact: 70
message: Msbuild.exe ran from an uncommon path on $dest$ execyted by $user$
mitre_attack_id:
- T1036
- T1127
- T1036.003
- T1127.001
observable:
- name: dest
type: Endpoint
role:
- Victim
- name: User
type: User
role:
- Victim
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
risk_score: 49
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1127.001/windows-sysmon.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: xmlwineventlog
update_timestamp: true