Detection: O365 Threat Intelligence Suspicious File Detected

Description

The following analytic identifies when a malicious file is detected within the Microsoft Office 365 ecosystem through the Advanced Threat Protection engine. Attackers may stage and execute malicious files from within the Microsoft Office 365 ecosystem. Any detections from built-in Office 365 capabilities should be monitored and responded to appropriately. Certain premium Office 365 capabilities such as Safe Attachment and Safe Links further enhance these detection and response functions.

1`o365_management_activity` Workload=ThreatIntelligence Operation=AtpDetection 
2| stats values(DetectionMethod) as category  values(FileData.FileName) as file_name values(FileData.FilePath) as file_path values(FileData.FileSize) as file_size values(FileData.MalwareFamily) as signature count, min(_time) as firstTime, max(_time) as lastTime by Id, UserId 
3| rename Id as signature_id, UserId as user 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `o365_threat_intelligence_suspicious_file_detected_filter`

Data Source

No data sources specified for this detection.

Macros Used

Name Value
o365_management_activity sourcetype=o365:management:activity
o365_threat_intelligence_suspicious_file_detected_filter search *
o365_threat_intelligence_suspicious_file_detected_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1204.002 Malicious File Execution
T1204 User Execution Execution
KillChainPhase.INSTALLATION
NistCategory.DE_CM
Cis18Value.CIS_10
APT-C-36
APT12
APT19
APT28
APT29
APT30
APT32
APT33
APT37
APT38
APT39
Ajax Security Team
Andariel
Aoqin Dragon
BITTER
BRONZE BUTLER
BlackTech
CURIUM
Cobalt Group
Confucius
Dark Caracal
DarkHydrus
Darkhotel
Dragonfly
EXOTIC LILY
Earth Lusca
Elderwood
FIN4
FIN6
FIN7
FIN8
Ferocious Kitten
Gallmaker
Gamaredon Group
Gorgon Group
HEXANE
Higaisa
Inception
IndigoZebra
Indrik Spider
Kimsuky
Lazarus Group
LazyScripter
Leviathan
Machete
Magic Hound
Malteiro
Mofang
Molerats
Moonstone Sleet
MuddyWater
Mustang Panda
Naikon
Nomadic Octopus
OilRig
PLATINUM
PROMETHIUM
Patchwork
RTM
Rancor
RedCurl
Saint Bear
Sandworm Team
SideCopy
Sidewinder
Silence
Star Blizzard
TA2541
TA459
TA505
TA551
The White Company
Threat Group-3390
Tonto Team
Transparent Tribe
Tropic Trooper
WIRTE
Whitefly
Windshift
Wizard Spider
admin@338
menuPass
LAPSUS$
Scattered Spider

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

You must install the Splunk Microsoft Office 365 Add-on and ingest Office 365 management activity events. The threat intelligence workload is typically only visible to E3/E5 level customers.

Known False Positives

unknown

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
Threat Intelligence workload detected a malicious file [$file_name$] from user $user$ 50 50 100
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation Passing N/A N/A N/A
Unit Passing Dataset o365 o365:management:activity
Integration ✅ Passing Dataset o365 o365:management:activity

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range


Source: GitHub | Version: 2