| ID | Technique | Tactic |
|---|---|---|
| T1566 | Phishing | Initial Access |
| T1566.001 | Spearphishing Attachment | Initial Access |
| T1566.002 | Spearphishing Link | Initial Access |
Detection: O365 Email Reported By User Found Malicious
Description
The following analytic detects when an email submitted to Microsoft using the built-in report button in Outlook is found to be malicious. This capability is an enhanced protection feature that can be used within o365 tenants by users to report potentially malicious emails. This correlation looks for any submission that returns a Phish or Malware verdict upon submission.
Search
1`o365_management_activity` Workload=SecurityComplianceCenter Operation=AlertEntityGenerated Name="Email reported by user as*"
2| fromjson Data
3| rename _raw AS temp etps AS _raw
4| extract pairdelim=";" kvdelim=":"
5| rename _raw AS etps temp AS _raw
6| search RescanVerdict IN (Phish,Malware)
7| rex field=tsd "\<(?<src_user>.+)\>"
8| eval src_user = case(isnull(src_user),tsd,true(),src_user)
9| stats count min(_time) as firstTime max(_time) as lastTime values(ms) as subject values(RescanVerdict) as result values(tsd) as sender values(src_user) as src_user by AlertId,AlertEntityId,Operation,Name
10| rename Name as signature, AlertId as signature_id, AlertEntityId as user
11| `security_content_ctime(firstTime)`
12| `security_content_ctime(lastTime)`
13| `o365_email_reported_by_user_found_malicious_filter`
Data Source
No data sources specified for this detection.
Macros Used
| Name | Value |
|---|---|
| o365_management_activity | sourcetype=o365:management:activity |
| o365_email_reported_by_user_found_malicious_filter | search * |
o365_email_reported_by_user_found_malicious_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
KillChainPhase.DELIVERY
NistCategory.DE_CM
Cis18Value.CIS_10
Axiom
GOLD SOUTHFIELD
INC Ransom
APT-C-36
APT1
APT12
APT19
APT28
APT29
APT30
APT32
APT33
APT37
APT38
APT39
APT41
Ajax Security Team
Andariel
BITTER
BRONZE BUTLER
BlackTech
CURIUM
Cobalt Group
Confucius
DarkHydrus
Darkhotel
Dragonfly
EXOTIC LILY
Elderwood
FIN4
FIN6
FIN7
FIN8
Ferocious Kitten
Gallmaker
Gamaredon Group
Gorgon Group
Higaisa
Inception
IndigoZebra
Kimsuky
Lazarus Group
LazyScripter
Leviathan
Machete
Malteiro
Mofang
Molerats
Moonstone Sleet
MuddyWater
Mustang Panda
Naikon
Nomadic Octopus
OilRig
PLATINUM
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
Windshift
Winter Vivern
Wizard Spider
admin@338
menuPass
APT1
APT29
APT3
APT32
APT33
APT39
BlackTech
Cobalt Group
Confucius
EXOTIC LILY
Earth Lusca
Elderwood
Evilnum
FIN4
FIN7
FIN8
Kimsuky
Lazarus Group
LazyScripter
Leviathan
LuminousMoth
Machete
Magic Hound
Mofang
Molerats
MuddyWater
Mustang Panda
Mustard Tempest
OilRig
Patchwork
RedCurl
Sandworm Team
Sidewinder
TA2541
TA505
TA577
Transparent Tribe
Turla
Windshift
Wizard Spider
ZIRCONIUM
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. You must deploy/allow the usage of the Microsoft Office Report A Message function.
Known False Positives
unknown
Associated Analytic Story
Risk Based Analytics (RBA)
| Risk Message | Risk Score | Impact | Confidence |
|---|---|---|---|
| The user $user$ reported an email classified as $result$ from $src_user$ | 75 | 75 | 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