Detection: MOVEit Empty Key Fingerprint Authentication Attempt

Updated Date: 2024-07-24 ID: 1a537acc-199f-4713-b5d7-3d98c05ab932 Author: Michael Haag, Splunk Type: Hunting Product: Splunk Enterprise Security

Description

This detection identifies attempts to authenticate with an empty public key fingerprint in Progress MOVEit Transfer, which is a key indicator of potential exploitation of the CVE-2024-5806 vulnerability. Such attempts are characteristic of the authentication bypass technique used in this vulnerability, where attackers try to impersonate valid users without providing proper credentials. While occasional empty key fingerprint authentication attempts might occur due to misconfigurations, a sudden increase or attempts from unexpected sources could signify malicious activity. This analytic helps security teams identify and investigate potential exploitation attempts of the MOVEit Transfer authentication bypass vulnerability.

1`moveit_sftp_logs` "UserAuthRequestHandler: SftpPublicKeyAuthenticator: Attempted to authenticate empty public key fingerprint" 
2| stats count by source _raw 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `moveit_empty_key_fingerprint_authentication_attempt_filter`

Data Source

Name Platform Sourcetype Source Supported App
N/A N/A N/A N/A N/A

Macros Used

Name Value
moveit_sftp_logs sourcetype="sftp_server_logs"
moveit_empty_key_fingerprint_authentication_attempt_filter search *
moveit_empty_key_fingerprint_authentication_attempt_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
T1190 Exploit Public-Facing Application Initial Access
KillChainPhase.DELIVERY
NistCategory.DE_AE
Cis18Value.CIS_10
APT28
APT29
APT39
APT41
APT5
Axiom
BackdoorDiplomacy
BlackTech
Blue Mockingbird
Cinnamon Tempest
Dragonfly
Earth Lusca
FIN13
FIN7
Fox Kitten
GALLIUM
GOLD SOUTHFIELD
HAFNIUM
Ke3chang
Kimsuky
Magic Hound
Moses Staff
MuddyWater
Rocke
Sandworm Team
Threat Group-3390
ToddyCat
Volatile Cedar
Volt Typhoon
menuPass

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 Risk Event False
This configuration file applies to all detections of type hunting.

Implementation

The MOVEit logs must be collected in Splunk. Currently, there is no TA available for MOVEit. Modify the analytic as needed to match the log format of your environment.

Known False Positives

False positives may occur, therefore utilize the analytic as a jump off point to identify potential empty key fingerprint authentication attempts.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
Potential exploitation of the CVE-2024-5806 vulnerability in Progress MOVEit Transfer, causing empty key fingerprint authentication attempts via $source$. 9 30 30
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 sftp_server_logs sftp_server_logs
Integration ✅ Passing Dataset sftp_server_logs sftp_server_logs

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: 1